docs copyedit: minor.

highlighters/cursor/README.md

@@ -1,5 +1,5 @@
 zsh-syntax-highlighting / highlighters / cursor
-=================================================
+===============================================
 
 This is the `cursor` highlighter, that highlights the cursor.
 

highlighters/line/README.md

@@ -1,5 +1,5 @@
 zsh-syntax-highlighting / highlighters / line
-=================================================
+=============================================
 
 This is the `line` highlighter, that highlights the whole line.
 

highlighters/root/README.md

@@ -1,5 +1,5 @@
 zsh-syntax-highlighting / highlighters / root
-=================================================
+=============================================
 
 This is the `root` highlighter, that highlights the whole line if the current user is root.
 

tests/README.md

@@ -23,7 +23,7 @@ subsequent tests.  The current working directory of tests is set to a newly-crea
 which is automatically cleaned up after the test exits.
 
 
-highlighting test
+Highlighting test
 -----------------
 
 [`test-highlighting.zsh`](tests/test-highlighting.zsh) tests the correctness of the highlighting. Usage:
@@ -37,7 +37,7 @@ All tests may be run with
 which will run all highlighting tests and report results in [TAP](http://testanything.org/) format.
 
 
-performance test
+Performance test
 ----------------
 
 [`test-perfs.zsh`](tests/test-perfs.zsh) measures the time spent doing the highlighting. Usage: