Update documentation

Author: snuggs

styles/icons.css

@@ -16,6 +16,7 @@
   - Emoji Database - https://emojidb.org
   - Test Icons - https://dev.w3.org/SVG/profiles/1.1F2/test/images
   - What Character? https://babelstone.co.uk/Unicode/whatisit.html
+  - Whitespace - https://en.wikipedia.org/wiki/Whitespace_character
   - URL Schemes - https://en.wikipedia.org/wiki/Uniform_Resource_Identifier
   - Useful Symbols - https://en.wikibooks.org/wiki/Unicode/List_of_useful_symbols
   - Apple URL Protocol Schemes - https://developer.apple.com/library/archive/featuredarticles/iPhoneURLScheme_Reference/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007899