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/notebooks.html

@@ -1,13 +1,13 @@
 <h1 id="notebook" class="anchor"><a href="#notebook"><i class="fas fa-link anchor-icon"></i></a> Digital Notebook</h1>
 
 <div class="alert alert-warning" role="alert">
-  <strong>If you are currently using an application like Evernote, Google Keep or Microsoft OneNote you should pick an alternative here.</strong>
+  <strong>If you are currently using an application like Evernote, Google Keep, or Microsoft OneNote, you should pick an alternative here.</strong>
 </div>
 
 {% include cardv2.html
 title="Joplin"
 image="/assets/img/tools/Joplin.png"
-description="Joplin is a free, open source, fully featured note taking and to-do application, which can handle a large number of markdown notes organized into notebooks and tags. It offers E2EE encryption and can sync through Nextcloud, Dropbox and more. It also offers easy import from Evernote and plain text notes."
+description="Joplin is a free, open-source, and fully-featured note-taking and to-do application which can handle a large number of markdown notes organized into notebooks and tags. It offers end-to-end encryption and can sync through Nextcloud, Dropbox, and more. It also offers easy import from Evernote and plain-text notes."
 website="https://joplinapp.org/"
 github="https://github.com/laurent22/joplin"
 windows="https://joplinapp.org/#desktop-applications"
@@ -61,6 +61,6 @@ chrome="https://chrome.google.com/webstore/detail/turtl/dgcojenhfdjhieoglmiaheih
 
 <ul>
   <li><a href="https://github.com/notable/notable">Notable</a> - The markdown-based note-taking app that doesn't suck.</li>
-  <li><a href="https://paperwork.cloud/">Paperwork</a> - Open source and self-hosted solution. For PHP / MySQL servers.</li>
+  <li><a href="https://paperwork.cloud/">Paperwork</a> - An open-source and self-hosted solution. For PHP / MySQL servers.</li>
   <li><a href="https://orgmode.org">Org-mode</a> - A major mode for GNU Emacs. Org-mode is for keeping notes, maintaining TODO lists, planning projects, and authoring documents with a fast and effective plain-text system. </li>
 </ul>