In the visual markdown editor, Cmd+B (bold) and Cmd+I (italic) now remove
the markdown delimiters when the cursor or selection is already inside a
bold/italic span, instead of always adding another wrapper. Mirrors the
toggle behavior of the visual LaTeX editor.
Issue #34826
GitOrigin-RevId: d9ced8493dfaa28b61f3f0d51479d95f62e0bc4a
* Update Copybara options in preparation for open-sourcing the source editor
* Move files
* Update paths
* Remove source-editor module and checks for its existence
* Explicitly mention CM6 license in files that contain code adapted from CM6
GitOrigin-RevId: 89b7cc2b409db01ad103198ccbd1b126ab56349b