Update devGuide for translating symbols, gestures, character descriptions (#17590)
Closes #16372
Summary of the issue:
Dev guide is out of date on translating symbols, character descriptions and gestures. It refers to the SVN process which is now deprecated. We only accept changes to these files via PR now.
Description of user facing changes
Update dev guide to refer to opening a PR via the GitHub interface rather than using SVN.
Translators will receive an email to nvda-l10 google group notifying them of changes to symbols and character description files.
Description of development approach
Created a GitHub action to send email to the google group using AWS SES.