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/perl/README.md

@@ -1,18 +1,16 @@
-Perl
-====
+# Perl
 
 Enables local [Perl][1] module installation on macOS and defines aliases.
 
-Local Module Installation
--------------------------
+## Local Module Installation
 
 Perl versions older than 5.14 do not support the local installation of Perl
 modules natively. This module allows for local installation of Perl modules on
-macOS in *~/Library/Perl/5.12* by altering the environment.
+macOS in *`~/Library/Perl/5.12`* by altering the environment.
 
 ### Usage
 
-For Perl versions older than 5.14, install *local::lib*.
+For Perl versions older than 5.14, install *`local::lib`*.
 
 ```console
 curl -L -C - -O http://search.cpan.org/CPAN/authors/id/A/AP/APEIRON/local-lib-1.008004.tar.gz
@@ -28,67 +26,62 @@ Install *cpanminus*:
 curl -L http://cpanmin.us | perl - --self-upgrade
 ```
 
-Perlbrew
---------
+## Perlbrew
 
 An alternative to the above is to use [Perlbrew][2], which allows for the
 management of multiple, isolated Perl installations in the home directory.
 
-plenv
------
+## plenv
 
-Yet another alternative is [plenv][3]. This is inspired from rbenv and enables
-switching between multiple binary installations.
+Yet another alternative is [*plenv*][3]. This is inspired from *rbenv* and
+enables switching between multiple binary installations.
 
-The subcommands of plenv is similar with rbenv.
+The subcommands of *plenv* is similar with *rbenv*.
 
-Aliases
--------
+## Aliases
 
 ### General
 
-  - `pl` is short for `perl`.
-  - `pld` looks up Perl documentation (`perldoc`).
-  - `ple` executes a one line program in a loop (`perl -wlne`).
+- `pl` is short for `perl`.
+- `pld` looks up Perl documentation (`perldoc`).
+- `ple` executes a one line program in a loop (`perl -wlne`).
 
-### Perlbrew
+### Perlbrew (plb)
 
-  - `plb` manages Perl environments.
-  - `plba` lists available Perl versions.
-  - `plbi` installs a Perl version.
-  - `plbl` lists installed Perl versions.
-  - `plbo` temporarily turns off Perlbrew.
-  - `plbO` turns off Perlbrew.
-  - `plbs` switches to a Perl version.
-  - `plbu` uninstalls a Perl version.
-  - `plbx` temporarily sets the Perl version to use.
+- `plb` manages Perl environments.
+- `plba` lists available Perl versions.
+- `plbi` installs a Perl version.
+- `plbl` lists installed Perl versions.
+- `plbo` temporarily turns off Perlbrew.
+- `plbO` turns off Perlbrew.
+- `plbs` switches to a Perl version.
+- `plbu` uninstalls a Perl version.
+- `plbx` temporarily sets the Perl version to use.
 
-### plenv
+### plenv (plv)
 
-  - `plv` manages Perl environments.
-  - `plvc` List all available plenv commands.
-  - `plvl` Set or show the local application-specific Perl version.
-  - `plvg` Set or show the global Perl version.
-  - `plvs` Set or show the shell-specific Perl version.
-  - `plvi` Install a Perl version using the perl-build plugin.
-  - `plvu` Uninstall a specific Perl version.
-  - `plvr` Rehash plenv shims (run this after installing executables).
-  - `plvv` Show the current Perl version and its origin.
-  - `plvV` List all Perl versions available to plenv.
-  - `plvw` Display the full path to an executable.
-  - `plvW` List all Perl versions that contain the given executable.
-  - `plvm` List cpan modules in current perl.
-  - `plvM` Migrate cpan modules from other version.
-  - `plvI` Install cpanm.
+- `plv` manages Perl environments.
+- `plvc` List all available plenv commands.
+- `plvl` Set or show the local application-specific Perl version.
+- `plvg` Set or show the global Perl version.
+- `plvs` Set or show the shell-specific Perl version.
+- `plvi` Install a Perl version using the perl-build plugin.
+- `plvu` Uninstall a specific Perl version.
+- `plvr` Rehash plenv shims (run this after installing executables).
+- `plvv` Show the current Perl version and its origin.
+- `plvV` List all Perl versions available to plenv.
+- `plvw` Display the full path to an executable.
+- `plvW` List all Perl versions that contain the given executable.
+- `plvm` List cpan modules in current perl.
+- `plvM` Migrate cpan modules from other version.
+- `plvI` Install cpanm.
 
-Functions
----------
+## Functions
 
-  - `perl-info` exposes information about the Perl environment via the
-    `$perl_info` associative array.
+- `perl-info` exposes information about the Perl environment via the
+  `$perl_info` associative array.
 
-Theming
--------
+## Theming
 
 To display the name of the current Perl version in a prompt, define the
 following style in the `prompt_name_setup` function.
@@ -101,14 +94,13 @@ zstyle ':prezto:module:perl:info:version' format 'version:%v'
 Then add `$perl_info[version]` to `$PROMPT` or `$RPROMPT` and call
 `perl-info` in the `prompt_name_precmd` hook function.
 
-Authors
--------
+## Authors
 
 *The authors of this module should be contacted via the [issue tracker][4].*
 
-  - [Sorin Ionescu](https://github.com/sorin-ionescu)
+- [Sorin Ionescu](https://github.com/sorin-ionescu)
 
-[1]: http://www.perl.org
-[2]: http://perlbrew.pl
+[1]: https://www.perl.org
+[2]: https://perlbrew.pl
 [3]: https://github.com/tokuhirom/plenv
 [4]: https://github.com/sorin-ionescu/prezto/issues