Started 4.1.2 development.
Docs fix.
#10389 Invalid closing tag </tr> in a sample "Text and Table" template
Added script to automatically fix lang/availableLang properties in plugins. Fixed some plugins on first run.
Minor changelog fix.
Fixed wrong markup in README.md.
Update BACKSPACE key state in blockedKeystrokes when using editor.setReadOnly().
Changelog entry.
Merge branch 't/9761'
<one-line summary, followed by blank line and full summary>

Test Plan:
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