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/macports/README.md

@@ -1,25 +1,22 @@
-MacPorts
-========
+# MacPorts
 
 Defines MacPorts aliases and adds MacPorts directories to path variables.
 
-Aliases
--------
+## Aliases
 
-  - `portc` cleans the files used to build ports.
-  - `porti` installs a port.
-  - `ports` searches for a port.
-  - `portu` upgrades a port.
-  - `portU` upgrades MacPorts, the ports collection, and outdated ports.
-  - `portx` uninstalls a port.
-  - `portX` uninstalls inactive ports.
+- `portc` cleans the files used to build ports.
+- `porti` installs a port.
+- `ports` searches for a port.
+- `portu` upgrades a port.
+- `portU` upgrades MacPorts, the ports collection, and outdated ports.
+- `portx` uninstalls a port.
+- `portX` uninstalls inactive ports.
 
-Authors
--------
+## Authors
 
 *The authors of this module should be contacted via the [issue tracker][1].*
 
-  - [Matt Cable](https://github.com/curiousstranger)
-  - [Sorin Ionescu](https://github.com/sorin-ionescu)
+- [Matt Cable](https://github.com/curiousstranger)
+- [Sorin Ionescu](https://github.com/sorin-ionescu)
 
 [1]: https://github.com/sorin-ionescu/prezto/issues