Add to the Contributing.md file

Author: ingydotnet

.github/Contributing.md

@@ -1,5 +1,10 @@
 ## Bash Style Conventions
 
+The most important thing re coding style (as with any contribution) is to
+follow the style conventions in place for the existing code.
+
+Here are some basics:
+
 * Use spaces for indentation.
   No tabs please.
 * Use 4 space indent.
@@ -12,6 +17,7 @@
 * Function names should be `foo-bar` not `foo_bar`.
 * Define functions `foo-bar() ( ... )`, not `function foo-bar ( ... )`.
 
+
 ## Testing
 
 * Run `make test`.