Fix some typos, grammar, etc., and add details (#1418)

* Fix some typos, grammar, etc. on the site

Fixes some issues with typos, capitalization, grammar, and et cetera.

* Fix typo, grammar, etc. in repository

* Update README.md
Mention Discourse community earlier, add missing period

* Update CONTRIBUTING.md
i.e. is used for equivalence or clarification while e.g. is for
examples. For instance, we shouldn't say that IMAP is equivalent or an
explanation to all open-source software used to access email (e.g.
there's POP3, open-source clients to access when there isn't IMAP such
as Tutanota, etc.).

We also shouldn't call IMAP open-source software since it's a protocol.

* Change "socially motivated

* Apply suggestions from code review

Co-Authored-By: Jonah Aragon <jonah@triplebit.net>

* Suggestion from code review with extras

* 'Kill switch' to 'Killswitch"

* Consistency and minor additions to details

- More parallel sentence structures, following <Name> <Verb phrase>
for the first sentence of cards. Related to issue #1420.
- Make Njalla parallel to the others, and mention Njalla
is based in Nevis with VPS in Sweden
- Don't use "us" when talking about external services
- Orange Website also provides domain registration
- Update capitalization and add more hyphens
- Mention that TOS;DR evaluations are done by the community and that
  they also evaluate privacy policies (see https://edit.tosdr.org/about)
- "E2EE encryption" is redundant since "E2EE" already has "encryption"
in it. Might as well expand it since full term is used later on.
- <Name> <Verb phrase> structure for Magic Wormhole
- For consistency, don't start Worth Mentioning entries with the name
- https://english.stackexchange.com/questions/27707/post-hyphenation-of-split-compound-words
- All the other "alert alert-warning" don't repeat the generic name and 
we also don't say 'a software'

* instant-messenger: Remove <em>, more cleanup

* voice-video-messenger: Hyphens and cleanup

- We don't say "a software" so replace it with something that works

* paste-services: Cleanup & change cryptography info

As per CryptPad's whitepaper and FAQ:
https://cryptpad.fr/faq.html#security-crypto
https://blog.cryptpad.fr/images/CryptPad-Whitepaper-v1.0.pdf

Fixes #1417.

* encryption: "open-source"

* Page descriptions and other cleanup

_includes/sections/self-contained-networks.html

@@ -21,7 +21,7 @@
   url="https://geti2p.net/"
   footer="OS: Windows, macOS, Linux, Android, BSD / Solaris."
   description="The Invisible Internet Project (I2P) is a computer network layer that allows applications to send messages to each other pseudonymously and securely. Uses include anonymous
-  Web surfing, chatting, blogging and file transfers. The software that implements this layer is called an I2P router and a computer running I2P is called an I2P node. The software is free and open source and is published under multiple licenses."
+  Web surfing, chatting, blogging, and file transfers. The software that implements this layer is called an I2P router and a computer running I2P is called an I2P node. The software is free and open-source and is published under multiple licenses."
   %}
 
   {% include card.html color="warning"
@@ -45,8 +45,8 @@
 <h3>Worth Mentioning</h3>
 
 <ul>
-  <li><a href="https://zeronet.io/">ZeroNet</a> - Open, free and uncensorable websites, using Bitcoin cryptography and BitTorrent network.</li>
-  <li><a href="https://retroshare.cc/">RetroShare</a> - Open Source cross-platform, Friend-2-Friend and secure decentralized communication platform.</li>
+  <li><a href="https://zeronet.io/">ZeroNet</a> - Open, free, and uncensorable websites, using Bitcoin cryptography and BitTorrent network.</li>
+  <li><a href="https://retroshare.cc/">RetroShare</a> - An open source, cross-platform, friend-to-friend, secure, and decentralized communication platform.</li>
   <li><a href="https://gnunet.org/">GNUnet</a> - GNUnet provides a strong foundation of free software for a global, distributed network that provides security and privacy.</li>
   <li><a href="https://ipfs.io/">IPFS</a> <em>and</em> <a href="https://github.com/ipfs-shipyard/ipfs-companion">IPFS Companion</a>- A peer-to-peer hypermedia protocol to make the web faster, safer, and more open. IPFS Companion is a browser extension for redirecting queries to a gateway of your choice (generally local). <a href="https://github.com/privacytoolsIO/privacytools.io/pull/361#issuecomment-344414022">
     <span class="badge badge-danger" data-toggle="tooltip" title="">
@@ -54,5 +54,5 @@
         Important privacy warning
       </span>
           </a></li>
-  <li><a href="https://yggdrasil-network.github.io/">Yggdrasil</a> - An early-stage implementation of a fully end-to-end encrypted IPv6 network. It is lightweight, self-arranging, supported on multiple platforms and allows pretty much any IPv6-capable application to communicate securely with other Yggdrasil nodes. Yggdrasil does not require you to have IPv6 Internet connectivity - it also works over IPv4. <span class="badge badge-warning" data-toggle="tooltip" title="The project is currently in early stages but it is being actively developed.">experimental <i class=\"far fa-question-circle\"></i></span> <span class="badge badge-danger" data-toggle="tooltip" title="Yggdrasil doesn't have a goal of providing anonymity and your peers know your IP address unless you are only using Tor/I2P peers.">privacy warning <i class="far fa-question-circle"></i></span></li>
+  <li><a href="https://yggdrasil-network.github.io/">Yggdrasil</a> - An early-stage implementation of a fully end-to-end encrypted IPv6 network. It is lightweight, self-arranging, supported on multiple platforms, and allows pretty much any IPv6-capable application to communicate securely with other Yggdrasil nodes. Yggdrasil does not require you to have IPv6 Internet connectivity - it also works over IPv4. <span class="badge badge-warning" data-toggle="tooltip" title="The project is currently in early stages but it is being actively developed.">experimental <i class=\"far fa-question-circle\"></i></span> <span class="badge badge-danger" data-toggle="tooltip" title="Yggdrasil doesn't have a goal of providing anonymity and your peers know your IP address unless you are only using Tor/I2P peers.">privacy warning <i class="far fa-question-circle"></i></span></li>
 </ul>