Idea: one-click Railway deploy alongside the InstaPods option

[hmseeb]

Raising this in Discussions first per CONTRIBUTING, before writing any code.

The idea: add a Railway one-click deploy option, alongside the InstaPods button already in
the badge row, plus a line in How to Install Dawarich.

Why it might be worth it: the two documented install routes are Docker and Synology, and the
InstaPods button covers managed hosting. Railway is a second option in that same lane, and it's
one where the whole stack — Dawarich, PostgreSQL, Redis — comes up wired together with
migrations run on boot, HTTPS on an assigned domain, and no .env to edit. For a self-hosted
location tracker, the people most motivated to get off Google Timeline are often the least
equipped to run three containers, so a second no-server option seems to fit the audience.

Why it might not be: your contributing guide says purely cosmetic changes generally aren't
accepted, and I can see a reading where a second deploy badge is exactly that. You may also not
want to accumulate hosting vendors in the README. Both are fair, which is why I'm asking rather
than sending a PR.

Scope if you want it: one badge added to the row on line 3, and one bullet under How to
Install Dawarich. Two lines, against dev. Marked community-maintained, not an official build.

Verified: deployed the template twice from scratch today. All three services come up healthy
first time with no retries, migrations run, /api/v1/health returns {"status":"ok"}, and the
app serves over HTTPS on the assigned domain.

Disclosure: I maintain the template, and Railway pays template authors a share of what
deployments spend. So I'm not neutral here — judge it on whether it helps your users. If you'd
prefer the template under the Dawarich name instead of mine, I'm happy to transfer it.