Improve Extensions documentation (#362)

Co-authored-by: eskild <[email protected]>

docs/docs/community/plugins.md

@@ -0,0 +1,16 @@
+---
+id: plugins
+title: Plugins (Extensions)
+description: List of Nebari plugins
+---
+
+Nebari plugins (sometimes referred to as extensions) allow developers to add new features relatively easily without the need to modify the core Nebari code base. At the moment, there are two types of plugins `stages` and `subcommands`. Stage plugins allow users to deploy new features alongside the existing the Nebari features whereas subcommand plugins allow users to extend or modify the existing Nebari CLI.
+
+You can learn to use and create Nebari extensions in the [extension mechanism documentation](/docs/how-tos/nebari-extension-system).
+
+## Verified community extensions
+
+The following community-developed extensions are recognized and verified by the Nebari development team.
+
+* [nebari-mlflow-aws](https://github.com/MetroStar/nebari-mlflow-aws)
+* [nebari-label-studio](https://github.com/MetroStar/nebari-label-studio)

docs/docs/how-tos/nebari-extension-system.md

@@ -4,15 +4,21 @@ title: Nebari Extension System
 description: An overview of the pluggy extension system for Nebari
 ---
 
+:::warning
+The Extension System was added recently in release 2023.9.1. It's in active development and might be unstable.
+
+We don't recommend using it in productions systems yet, but we'll appreciate your explorations, testing, and feedback. You can share your comments in [this GitHub Issue](https://github.com/nebari-dev/nebari/issues/1894).
+:::
+
 ## Introduction
 
 This guide is to help developers extend and modify the behavior of
-nebari. We leverage the plugin system
+Nebari. We leverage the plugin system
 [pluggy](https://pluggy.readthedocs.io/en/stable/) to enable easy
-extensibility. Currently Nebari supports:
+extensibility. Currently, Nebari supports:
 
  - overriding a given stages in a deployment
- - adding additional stages before, after and between existing stages 
+ - adding additional stages before, after and between existing stages
  - arbitrary subcommands
 
 We maintain an [examples
@@ -21,7 +27,7 @@ which contains up to date usable examples.
 
 ## Installing a plugin
 
-Registering a plugin should be easy for the end user. Pluggins are
+Registering a plugin should be easy for the end user. Plugins are
 either installed into your existing environment e.g.
 
 ```shell
@@ -30,7 +36,7 @@ pip install my-nebari-plugin
 
 Alternatively if you only want to temporarily add an extension.
 
-:::note 
+:::note
 `--import-plugin` does not work for loading subcommands due to
 cli already being constructed before plugin imports take place.
 :::
@@ -40,30 +46,35 @@ nebari --import-plugin path/to/plugin.py <command> ...
 nebari --import-plugin import.module.plugin.path <command> ...
 ```
 
+:::note
+Currently, Nebari does **not** support un-installing a plugin.
+You will need to destroy and re-deploy Nebari to remove any installed plugins.
+:::
+
 ## Developing an extension
 
 The most important step to developing a plugin is ensuring that the
 setuptools entrypoint is set.
 
-```toml:pyproject.toml
+<!-- Note: FormidableLabs/prism-react-renderer, tool used by Docusaurus to generate code blocks & highlight syntax does not support TOML, so we're using YAML highlighting below -->
 
+```yaml title="pyproject.toml"
 ...
 
 [project.entry-points.nebari]
 my-subcommand = "path.to.subcommand.module"
 
 ...
-
 ```
 
 Adding this one line to your `pyproject.toml` will ensure that upon
-installation of the package the nebari plugins are registered.
+installation of the package the Nebari plugins are registered.
 
 ### Subcommands
 
 Nebari exposes a hook `nebari_subcommand` which exposes the
-[typer](https://github.com/tiangolo/typer) cli instance. This allows
-the developer to attach and arbitrary number of subcommands.
+[typer](https://github.com/tiangolo/typer) CLI instance. This allows
+the developer to attach any arbitrary number of subcommands.
 
 ```python
 from nebari.hookspecs import hookimpl
@@ -87,14 +98,14 @@ There is a dedicated working example in [nebari-plugin-examples](https://github.
 ### Stages
 
 Nebari exposes a hook `nebari_stage` which uses the `NebariStage`
-class. The `NebriStage` exposes `render`, `deploy`, `destroy` as
-arbitrary functions called. See below for a complete example.
+class. `NebriStage` exposes `render`, `deploy`, `destroy` as
+arbitrary functions calls. See below for a complete example.
 
 Nebari decides the order of stages based on two things the `name: str`
 attribute and `priority: int` attribute. The rules are as follows:
  - stages are ordered by `priority`
  - stages which have the same `name` the one with highest priority
-   number is chosen.
+   number is chosen
 
 ```python
 import contextlib

docs/sidebars.js

@@ -115,6 +115,7 @@ module.exports = {
         "community/doc-contributions",
         "community/style-guide",
         "community/team-structure",
+        "community/plugins",
         {
           type: "category",
           label: "Maintainers",