general: Reformat documentation with better formatting and wording

General purpose reformating and rewording in (a few places). This should
also make markdown linting happier.

Prefer back-ticks wherever useful and use `console` for code blocks to
be executed on terminal.

Also, update references links wherever possible (including update from
'http://' to 'https://').

modules/autosuggestions/README.md

@@ -1,5 +1,4 @@
-Autosuggestions
-===============
+# Autosuggestions
 
 Integrates [zsh-autosuggestions][1] into Prezto, which implements the
 [Fish shell][2]'s autosuggestions feature, where the user can type in any part
@@ -13,15 +12,13 @@ If this module is used in conjunction with the *history-substring-search*
 module, this module must be loaded **after** the *history-substring-search*
 module.
 
-Contributors
-------------
+## Contributors
 
 New features and bug fixes should be submitted to the [zsh-autosuggestions][1]
 project according to its rules and regulations. This module will be synchronized
 against it.
 
-Settings
---------
+## Settings
 
 ### Highlighting
 
@@ -29,33 +26,31 @@ If colors are enabled, *autosuggestions* will automatically highlight
 positive results.
 
 To enable highlighting for this module only, add the following line to
-*zpreztorc*:
+*~/.zpreztorc*:
 
 ```sh
 zstyle ':prezto:module:autosuggestions' color 'yes'
 ```
 
-To set the query found color, add the following line to *zpreztorc*:
+To set the query found color, add the following line to *~/.zpreztorc*:
 
 ```sh
 zstyle ':prezto:module:autosuggestions:color' found ''
 ```
 
-Troubleshooting
----------------
+## Troubleshooting
 
 ### Autosuggestions from previous sessions don't show up
 
 For autosuggestions from previous shell sessions to work, please make sure you
 also have the `history` module enabled.
 
-Authors
--------
+## Authors
 
 *The authors of this module should be contacted via the [issue tracker][3].*
 
-  - [Sorin Ionescu](https://github.com/sorin-ionescu)
+- [Sorin Ionescu](https://github.com/sorin-ionescu)
 
 [1]: https://github.com/tarruda/zsh-autosuggestions
-[2]: http://fishshell.com
+[2]: https://fishshell.com
 [3]: https://github.com/sorin-ionescu/prezto/issues