Split development documentation in several separate pages, fixes for the sidebar menu

United similar sections at the intro page

Fix spelling

Update docs

docs/community/documentation.md

@@ -0,0 +1,106 @@
+> **Warning**
+>
+> ## THIS IS AN AUTOGENERATED FILE. DO NOT EDIT.
+>
+> ## Please edit the corresponding file in [/packages/mermaid/src/docs/community/documentation.md](../../packages/mermaid/src/docs/community/documentation.md).
+
+# Contributing Documentation
+
+**_\[TODO: This section is still a WIP. It still needs MAJOR revision.]_**
+
+If it is not in the documentation, it's like it never happened. Wouldn't that be sad? With all the effort that was put into the feature?
+
+The docs are located in the `packages/mermaid/src/docs` folder and are written in Markdown. Just pick the right section and start typing.
+
+The contents of [mermaid.js.org](https://mermaid.js.org/) are based on the docs from the `master` branch.
+Updates committed to the `master` branch are reflected in the [Mermaid Docs](https://mermaid.js.org/) once published.
+
+## How to Contribute to Documentation
+
+We are a little less strict here, it is OK to commit directly in the `develop` branch if you are a collaborator.
+
+The documentation is located in the `packages/mermaid/src/docs` directory and organized according to relevant subfolder.
+
+The `docs` folder will be automatically generated when committing to `packages/mermaid/src/docs` and **should not** be edited manually.
+
+```mermaid-example
+flowchart LR
+  classDef default fill:#fff,color:black,stroke:black
+
+  source["files in /packages/mermaid/src/docs\n(changes should be done here)"] -- automatic processing\nto generate the final documentation--> published["files in /docs\ndisplayed on the official documentation site"]
+
+```
+
+```mermaid
+flowchart LR
+  classDef default fill:#fff,color:black,stroke:black
+
+  source["files in /packages/mermaid/src/docs\n(changes should be done here)"] -- automatic processing\nto generate the final documentation--> published["files in /docs\ndisplayed on the official documentation site"]
+
+```
+
+You can use `note`, `tip`, `warning` and `danger` in triple backticks to add a note, tip, warning or danger box.
+Do not use vitepress specific markdown syntax `::: warning` as it will not be processed correctly.
+
+````
+```note
+Note content
+```
+
+```tip
+Tip content
+```
+
+```warning
+Warning content
+```
+
+```danger
+Danger content
+```
+
+````
+
+> **Note**
+> If the change is _only_ to the documentation, you can get your changes published to the site quicker by making a PR to the `master` branch.
+
+We encourage contributions to the documentation at [packages/mermaid/src/docs in the _develop_ branch](https://github.com/mermaid-js/mermaid/tree/develop/packages/mermaid/src/docs).
+
+**_DO NOT CHANGE FILES IN `/docs`_**
+
+## The official documentation site
+
+**[The mermaid documentation site](https://mermaid.js.org/) is powered by [Vitepress](https://vitepress.vuejs.org/).**
+
+To run the documentation site locally:
+
+1.  Run `pnpm --filter mermaid run docs:dev` to start the dev server. (Or `pnpm docs:dev` inside the `packages/mermaid` directory.)
+2.  Open <http://localhost:3333/> in your browser.
+
+Markdown is used to format the text, for more information about Markdown [see the GitHub Markdown help page](https://help.github.com/en/github/writing-on-github/basic-writing-and-formatting-syntax).
+
+To edit Docs on your computer:
+
+_\[TODO: need to keep this in sync with [check out a git branch in Contributing Code above](#1-checkout-a-git-branch) ]_
+
+1.  Create a fork of the develop branch to work on.
+2.  Find the Markdown file (.md) to edit in the `packages/mermaid/src/docs` directory.
+3.  Make changes or add new documentation.
+4.  Commit changes to your branch and push it to GitHub (which should create a new branch).
+5.  Create a Pull Request of your fork.
+
+To edit Docs on GitHub:
+
+1.  Login to [GitHub.com](https://www.github.com).
+2.  Navigate to [packages/mermaid/src/docs](https://github.com/mermaid-js/mermaid/tree/develop/packages/mermaid/src/docs) in the mermaid-js repository.
+3.  To edit a file, click the pencil icon at the top-right of the file contents panel.
+4.  Describe what you changed in the **Propose file change** section, located at the bottom of the page.
+5.  Submit your changes by clicking the button **Propose file change** at the bottom (by automatic creation of a fork and a new branch).
+6.  Visit the Actions tab in Github, `https://github.com/<Your Username>/mermaid/actions` and enable the actions for your fork. This will ensure that the documentation is built and updated in your fork.
+7.  Create a Pull Request of your newly forked branch by clicking the green **Create Pull Request** button.
+
+## Documentation organization: Sidebar navigation
+
+If you want to propose changes to how the documentation is _organized_, such as adding a new section or re-arranging or renaming a section, you must update the **sidebar navigation.**
+
+The sidebar navigation is defined in [the vitepress configuration file config.ts](../.vitepress/config.ts).