patch: work around pip's secure-install bug; bump version

- upstream issue: https://github.com/pypa/pip/issues/9644
- runs tests within a container, uses the same `dockerfile`
- ignores `pdm.lock`, removes `requirement.txt`
- update manual contribution steps
- bumps project version

**Related Items**

_Issues_

- Closes #137

.env.template

@@ -0,0 +1,27 @@
+# Do NOT edit this file, make
+# a copy and rename as `.env`
+
+INPUT_GH_TOKEN=
+INPUT_WAKATIME_API_KEY=
+# meta
+INPUT_API_BASE_URL=
+INPUT_REPOSITORY=
+# content
+INPUT_SHOW_TITLE=
+INPUT_SECTION_NAME=
+INPUT_BLOCKS=
+INPUT_CODE_LANG=
+INPUT_TIME_RANGE=
+INPUT_LANG_COUNT=
+INPUT_SHOW_TIME=
+INPUT_SHOW_TOTAL=
+INPUT_SHOW_MASKED_TIME=
+INPUT_STOP_AT_OTHER=
+# commit
+INPUT_COMMIT_MESSAGE=
+INPUT_TARGET_BRANCH=
+INPUT_TARGET_PATH=
+INPUT_COMMITTER_NAME=
+INPUT_COMMITTER_EMAIL=
+INPUT_AUTHOR_NAME=
+INPUT_AUTHOR_EMAIL=