fixup! syntax-checking: Improved documentation and clean-ups

Author: lebensterben

layers/+checkers/syntax-checking/README.org

@@ -6,7 +6,7 @@
 
 * Table of Contents                     :TOC_5_gh:noexport:
 - [[#description][Description]]
-  - [[#features][Features]]
+  - [[#features][Features:]]
 - [[#installation][Installation]]
 - [[#customization][Customization]]
   - [[#enable-flycheck-manually][Enable Flycheck Manually]]
@@ -20,7 +20,7 @@
 * Description
 This layer adds on-the-fly syntax checking to all supported language layers.
 
-** Features
+** Features:
 - Automatic syntax checking with [[http://www.flycheck.org/][Flycheck]] for various language layers.
 - Shows syntax error in pop-up window via [[https://github.com/flycheck/flycheck-pos-tip][flycheck-pos-tip]].