Update CHANGELOG and README

Add CHANGELOG.md

Merge pull request caxy#31 from caxy/feature-table_diffing

New Feature: Table Diffing

Merge pull request caxy#25 from caxy/fix/htmldiff-matching

Fix HtmlDiff matching logic skipping over single word matches

Merge pull request caxy#24 from caxy/feature/list-diff-fixes

Misc. list diffing updates and fixes

Merge pull request caxy#20 from caxy/feature-list_diffing-new

feature-list_diffing-new

Merge pull request caxy#19 from caxy/feature-list_diffing-new

Feature list diffing new

Merge pull request caxy#17 from caxy/feature-list_diffing-new

Fix: Updated code so that null is not given in list formatting.

Merge pull request caxy#16 from caxy/feature-list_diffing-new

Missed an array_column in ListDiff. Updated to use ArrayColumn function.

Merge pull request caxy#15 from caxy/feature-list_diffing-new

Added update for php versions that do not have array_column as a function.