Add Estonian translation

Props Lauri Säde
Update readme.md

Add @Laurisade as contributor for Estonian translations.
Updates to Estonian translation

props @Laurisade
Fix Customizer's font family selects not displaying correct value
Attempt to fix issues with attachment ID in logo class
Add missing action/filter PhpDocs
Update changelog for 1.4.7
Add sorting to googlefonts json_massager subtask
Bump version to 1.4.7
Merge branch 'release-1.4.7' into develop
Version 1.4.7