minor fixes throughout the docs

doc/authentication-methods/pki.md

@@ -15,4 +15,4 @@ These include:
 
 ## Configuration options
 
-None
+None.

doc/custom.css

@@ -4,6 +4,6 @@ img#mim-readme-logo {
 }
 
 :root {
-  --md-primary-fg-color:        #459bb6;
+  --md-primary-fg-color: #459bb6;
   --md-accent-fg-color: #0554b8;
 }

doc/migrations/3.7.0_4.0.0.md

@@ -17,7 +17,7 @@ If modified the code, e.g. by adding a custom extension module, you might want t
 
 ## OTP Logger as the logging framework
 
-We've transitioned from [lager](lager) to [Logger](Logger) as our logging framework.
+We've transitioned from [lager][lager] to [Logger][Logger] as our logging framework.
 No internal changes were introduced, and the default handlers still implement the same behaviour,
 but the configuration is different, though still done in the same place.
 To know more, please refer to each framework's documentation.

doc/modules/mod_blocking.md

@@ -1,13 +1,15 @@
 ## Module Description
+
 This module implements [XEP-0191: Blocking command](http://xmpp.org/extensions/xep-0191.html).
 The extension allows blocking the whole communication with a user (or a group of users) with a single command. 
 The protocol is much simpler than privacy lists.
 
 ## Options
 
-none
+None.
 
 ## Example Configuration
+
 ```toml
 [modules.mod_blocking]
 ```