Keep snippet vars definitions in a single format across all snippets and documentation.

The format is:

# var-name: value

Previously snippets used a mixture of the following formatting:

#var-name: value
#var-name : value
# var-name: value
# var-name : value

snippets/css-mode/bor

@@ -1,4 +1,4 @@
-#name : border size style color
+# name: border size style color
 # key: bor
 # --
 border: ${1:1px} ${2:solid} #${3:999};