Add diagram drawing capability

[tikimo]

Scope & Context

Example:

We want to have technical process description of certain functions in the form of a simple drawing. 
Similar tool libraries should be available. 
The ticket is about adding the custom field feature on Opportunities and Tasks pages only, as a tab just like "Files"

Current behavior

Can add Files which can be previewed

Example:

On Opportunities and Tasks pages, the "Files" tab has the option to upload files. 
The files can be previewed.

Expected behavior

"+ Add file" button should have option to add diagram, or a separate tab for diagrams

Example:

"+ Add file" button prompts to upload file or create a drawing. When adding drawing, the preview is the drawing editor.

Technical inputs

No take on the technical implementation.

The editor in the screenshot is from zadam/trilium

[Bonapara]

Hi! Converting it to a discussion