This includes changing the URL to #settings/preferences, with a
transparent redirect so that existing links, like the one from Welcome
Bot, continue to work.
Rename the 'language-time' title to 'General'. As the 'language-time'
section no longer exists, replace the 'lang-time-settings' classname
with the 'general-settings' classname in the 'settings_display.js' file.
Updated the 'change-the-time-format.md' and 'change-your-language.md'
documentation files to reflect these changes.
To pass the puppeteer_test Replaced the 'lang-time-settings-status'
classname to 'general-settings-status' inside 'settings.test.ts' file.
These files are not Jinja2 templates, so there's no reason that they needed
to be inside `templates/zerver`. Moving them to the top level reflects their
importance and also makes it feel nicer to work on editing the help center content,
without it being unnecessary buried deep in the codebase.