Languages
Markdown
Markdown is one of the most popular markup languages to add rich formatting, tables and images to your documentation using plain text documents.
Markdown files (.md) can be source-controlled along with your code.
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Tools:
Mermaid
Mermaid lets you create diagrams using text definitions that can later be rendered with a diagramming and charting tool.
Mermaid files (.mmd) can be source-controlled along with your code. It's also recommended to include image files (.png) with the rendered diagrams under source control. Your markdown files should link the image files, so they can be read without the need of a Mermaid rendering tool (e.g., during Pull Request review).
Example Mermaid diagram
This is an example of a Mermaid flowchart diagram written as code.
graph LR
A[Diagram Idea] -->|Write mermaid code| B(mermaid.mmd file)
B -->|Add to source control| C{Code repo}
B -->|Export as .png| G(.png file of diagram)
G -->|Add to source control| C
This is an example of how it can be rendered as an image.
More information:
Tools: