add dev install command

.devcontainer/postCreateCommands.sh

@@ -1,3 +1,4 @@
 pip install --upgrade pip > /tmp/pip.stdout.log 2> /tmp/pip.stderr.log
 pip install uv > /tmp/uv.stdout.log 2> /tmp/uv.stderr.log
 uv tool install tox --with tox-uv > /tmp/tox.stdout.log 2> /tmp/tox.stderr.log
+uv pip install -e .