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/social-networks.html

@@ -7,7 +7,7 @@
 {% include cardv2.html
 title="Mastodon - Twitter Alternative"
 image="/assets/img/tools/Mastodon.png"
-description='Mastodon is a social network based on open web protocols and free, open-source software. It is decentralized like e-mail. It also has the most users, and the most diverse (in terms of interests) users, looks good, and is easy to setup. Feel welcome to join our hosted instance: <a href="https://social.privacytools.io/">social.privacytools.io</a>'
+description='Mastodon is a social network based on open web protocols and free, open-source software. It is decentralized like email. It also has the most users, and the most diverse (in terms of interests) users; looks good; and is easy to setup. Feel welcome to join our hosted instance: <a href="https://social.privacytools.io/">social.privacytools.io</a>'
 website="https://joinmastodon.org/"
 forum="https://forum.privacytools.io/t/discussion-mastodon/289"
 github="https://github.com/tootsuite/mastodon"
@@ -51,7 +51,7 @@ web="https://friendi.ca/"
 {% include cardv2.html
 title="PixelFed - Instagram Alternative"
 image="/assets/img/provider/pixelfed.png"
-description='A free and ethical photo sharing platform, powered by ActivityPub federation. Pixelfed is an open-source, federated platform. You can run your own instance or <a href="https://fediverse.party/en/pixelfed/">join one.</a>'
+description='PixelFed is a free and ethical photo sharing platform, powered by ActivityPub federation. Pixelfed is an open-source, federated platform. You can run your own instance or <a href="https://fediverse.party/en/pixelfed/">join one.</a>'
 website="https://pixelfed.org/"
 forum="https://forum.privacytools.io/t/discussion-pixelfed/293"
 github="https://github.com/pixelfed"
@@ -61,7 +61,7 @@ web="https://pixelfed.org/"
 {% include cardv2.html
 title="GNU social - Twitter Alternative"
 image="/assets/img/provider/gnu-social.png"
-description="A social communication software for both public and private communications. It is widely supported and has a large userbase. It is already used by the Free Software Foundation."
+description="GNU social is social-communication software for both public and private communications. It is widely supported and has a large userbase. It is already used by the Free Software Foundation."
 website="https://gnu.io/social/"
 forum="https://forum.privacytools.io/t/discussion-gnu-social/292"
 gitlab="https://git.gnu.io/gnu/gnu-social/"
@@ -70,8 +70,8 @@ web="https://gnu.io/social/"
 
 <h3>Worth Mentioning</h3>
 <ul>
-  <li><a href="https://www.minds.com/">Minds</a> - An <a href="https://gitlab.com/minds">open source</a> and distributed social networking service, integrating the blockchain to reward the community.</li>
-  <li><a href="https://movim.eu/">Movim</a> - Federated social platform that relies on the XMPP standard and therefore allows you to exchange with many other clients on all devices.</li>
+  <li><a href="https://www.minds.com/">Minds</a> - An <a href="https://gitlab.com/minds">open-source</a> and distributed social networking service, integrating the blockchain to reward the community.</li>
+  <li><a href="https://movim.eu/">Movim</a> - A federated social platform that relies on the XMPP standard and therefore allows you to exchange with many other clients on all devices.</li>
 </ul>
 
 <h3>Related Information</h3>