docs(CHANGES) Add pipx, uv, and uvx installation options

Add pipx, uv, and uvx as installation methods for developmental releases
alongside pip, matching the pattern used in vcspull. Commands do not
reference specific prerelease versions.

Author: tony

CHANGES

@@ -8,6 +8,24 @@ To install the unreleased gp-libs version, see [developmental releases](https://
 $ pip install --user --upgrade --pre gp-libs
 ```
 
+[pipx](https://pypa.github.io/pipx/docs/):
+
+```console
+$ pipx install --suffix=@next 'gp-libs' --pip-args '\--pre' --force
+```
+
+[uv](https://docs.astral.sh/uv/):
+
+```console
+$ uv add gp-libs --prerelease allow
+```
+
+[uvx](https://docs.astral.sh/uv/guides/tools/):
+
+```console
+$ uvx --from 'gp-libs' --prerelease allow gp-libs
+```
+
 ## gp-libs 0.0.15 (unreleased)
 
 - _Add your latest changes from PRs here_