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/selfhosted-cloud.html

@@ -7,7 +7,7 @@
 {% include cardv2.html
 title="Nextcloud"
 image="/assets/img/provider/Nextcloud.png"
-description="Similar functionally to the widely used Dropbox, with the difference being that Nextcloud is free and open-source, and thereby allowing anyone to install and operate it without charge on a private server, with no limits on storage space or the number of connected clients."
+description="Nextcloud has similar functionally to the widely used Dropbox, with the difference being that Nextcloud is free and open-source, thereby allowing anyone to install and operate it without charge on a private server with no limits on storage space or the number of connected clients."
 website="https://nextcloud.com/"
 forum="https://forum.privacytools.io/t/discussion-nextcloud/287"
 windows="https://nextcloud.com/install/#install-clients"
@@ -28,7 +28,7 @@ image="/assets/img/tools/Tahoe-LAFS.png"
 image-dark="/assets/img/tools/Tahoe-LAFS-dark.png"
 website="https://www.tahoe-lafs.org/"
 forum="https://forum.privacytools.io/t/discussion-tahoe-lafs/1662"
-description="Tahoe-LAFS is a Free and Open decentralized cloud storage system. It distributes your data across multiple servers. Even if some of the servers fail or are taken over by an attacker, the entire file store continues to function correctly, preserving your privacy and security."
+description="Tahoe-LAFS is a free and open decentralized cloud storage system. It distributes your data across multiple servers. Even if some of the servers fail or are taken over by an attacker, the entire file store continues to function correctly, preserving your privacy and security."
 windows="https://github.com/tahoe-lafs/tahoe-lafs#via-pip"
 mac="https://github.com/tahoe-lafs/tahoe-lafs#via-pip"
 linux="https://github.com/tahoe-lafs/tahoe-lafs#using-os-packages"
@@ -38,5 +38,5 @@ git="https://www.tahoe-lafs.org/trac/tahoe-lafs/browser"
 
 <h3>Worth Mentioning</h3>
 <ul>
-  <li><a href="https://github.com/xwiki-labs/cryptpad/">CryptPad</a> - End-to-end encrypted real time collaboration sharing folders, media, and documents (open-source).</li>
+  <li><a href="https://github.com/xwiki-labs/cryptpad/">CryptPad</a> - An open-source and end-to-end encrypted real-time collaborative editor that lets you share folders, media, and documents.</li>
 </ul>