Update docs

docs/index.md

@@ -1,4 +1,4 @@
-# Mono Documentation
+# Monas Documentation
 
 ```{include} ../README.md
 :start-after: <!--index start-->
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 quickstart
 ```
 
+```{toctree}
+:hidden:
+
+integration
+```
+
 ```{toctree}
 :caption: CLI Reference
 

docs/integration.md

@@ -0,0 +1,40 @@
+# Integration
+
+**Monas** does not manage dependencies or environments itself, but it should work with most tools of Python packaging.
+
+## PEP 517 support
+
+Since subpackages are installed in **editable mode**, Monas supports all build backends that support editable installation.
+The list includes:
+
+1. [setuptools](https://setuptools.pypa.io/)
+2. [pdm](https://pdm.fming.dev/)
+3. [flit](https://flit.pypa.io/)
+4. [hatch](https://ofek.dev/hatch/latest/)
+
+Moreover, the above backends now all support [PEP 621]/[PEP 631] metadata, so Monas will initialize the project
+metadata with PEP 621 format stored in `pyproject.toml`. At present, Monas does not work with package
+managers that do not support PEP 621.
+
+[pep 621]: https://www.python.org/dev/peps/pep-0621/
+[pep 631]: https://www.python.org/dev/peps/pep-0631/
+
+## Installer
+
+Monas uses `virtualenv` and `pip` to install dependencies by creating a `.venv` folder under each subpackage.
+Fortunately, the above selected package managers can detect virtualenv automatically and you can start your work from it.
+
+```{note} Monas works the same in arbitrary sub directories in the project.
+
+```
+
+```{admonition} No lock files will be created
+:class: note
+
+Monas, however, does not create any lock files. This is to ensure the installation is fast and correct. That is to say,
+Monas doesn't talk with any package managers other than `pip`.
+
+Thanks to the standardization of PEP 621 and PEP 631, Monas is able to add new dependency lines into the
+`pyproject.toml` file in a uniform way. You can anyway use your favorite package managers from the subpackage directory
+and create lock files if necessary.
+```

docs/quickstart.md

@@ -40,6 +40,16 @@ See what packages are added:
 monas list
 ```
 
+## Install all packages and dependencies
+
+```bash
+monas install
+```
+
+Monas will create a virtualenv under each subpackage and install all dependencies into it.
+The subpackage itself and other subpackages, if required, are installed in **editable mode**.
+That is to say, any changes locally will take effect immediately.
+
 ## Add dependencies to the subpackages
 
 ```bash