webdoc: bundle Py installation instructions (#707)

hugo/content/installation/_index.md

hugo/content/installation/building/_index.md

hugo/content/installation/building/unix/third-party.md

hugo/content/installation/building/windows/index.md

hugo/content/installation/install/_index.md

hugo/content/installation/install/linux.md

hugo/content/installation/install/macos.md

hugo/content/installation/install/windows.md

hugo/content/installation/install/windows/_index.md

hugo/content/installation/py/_index.md

hugo/content/installation/py/linux.md

hugo/content/installation/py/mac.md

hugo/content/installation/py/modules.md

hugo/content/installation/py/win.md

hugo/hugo.toml

hugo/layouts/shortcodes/recommended-python.html

hugo/static/img/win_add_to_PATH.png

hugo/static/img/win_dll_not_found.png

hugo/static/img/win_path.png