Transition from Mercurial to Git:

Repository has been converted to Git using fast-export
(https://github.com/frej/fast-export).

The following command has been used:
```sh
$ ../fast-export/hg-fast-export.sh -r ../hg-libervia-backend --hg-hash -M main
```

That means that previous HG hashes are annotated in the `hg` namespace.

`.hgignore` has been converted to `.gitignore`, and `_trial_temp/` has been removed as we
nowadays use `pytest` instead of `trial`.

While Mercurial is a great tool, more and more tools are only compatible with Git (e.g.,
ripgrep), and in particular `uv`, which becomes the new packaging de-facto standard in
Python. Also, many developers are more at ease with Git (even if Mercurial is actually
simpler to use).

.gitignore

@@ -0,0 +1,43 @@
+# Build directories
+bridge_constructor/generated
+build
+ctags_links/
+dist/
+.eggs/
+env/
+libervia_backend.egg-info/
+MANIFEST
+.mypy_cache/
+
+# Python artifacts
+*.orig
+*.pyc
+*.pyo
+.pytest_cache
+*.pyv
+
+# Editor files
+Session.vim
+*.swo
+*.swp
+.vim
+
+# IDE
+.vscode
+
+# Type stubs
+stubs/
+
+# Generated files
+tags
+
+# Test reports
+tests/e2e/report*
+
+# Twisted logs and state
+twistd.log
+twistd.pid
+twisted/plugins/dropin.cache
+
+# Backup files
+*.un~