Fixes#31251.
All these values have been taken from `sidebar_index.md`. We will worry
about syncing that file and the starlight sidebar config option later on
during the `help-beta` migration.
Instead of using `.home-link` class to insert the black left-pointing
triangle, we are just using the unicode character directly in
astro.config.mjs.
We've also added a class because we wanted a section header in sidebar
for `Zulip Administration` without it acting as a group for all the
links below it. It is bit of a hacky approach but workable for now
considering we only have 1 instance where we are using it. `rem` was
used as the unit for font-size since that is the unit being used by
starlight for it's font size too.
We also add the `run-dev` commands to `/devtools` page. The GitHub
issue link is duplicated between both, but it's a useful duplication
and the link is unlikely to change.
We are adding MDX files to `.gitignore` for now since they are
just a result of a build process, once the migration is done,
we will not ignore them.
We're using PNPM workspaces to manage this project.
The new project's tsconfig.json has been copied from the current
root tsconfig.json while omitting some details that are only
relevant to that project.
`help-beta/src/env.d.ts` is a type declaration file auto-generated
by Astro. See https://github.com/withastro/astro/issues/6013.