message: docs: update file extensions in CIDER editor documentation
diff: @@ -21,14 +21,14 @@ caret nodes (more on that later).
  For these reasons it doesn't use `innerText`, `textContent` or anything similar.
  The model addresses any content in the editor within as an offset within this string.
  The caret position is thus also converted from a position in the DOM tree
  -to an offset in the content string. This happens in `getCaretOffsetAndText` in `dom.js`.
  +to an offset in the content string. This happens in `getCaretOffsetAndText` in `dom.ts`.
  Once the content string and caret offset is calculated, it is passed to the `update()`
  method of the model. The model first calculates the same content string of its current parts,
  basically just concatenating their text. It then looks for differences between
  the current and the new content string. The diffing algorithm is very basic,
  and assumes there is only one change around the caret offset,
  -so this should be very inexpensive. See `diff.js` for details.
  +so this should be very inexpensive. See `diff.ts` for details.
  The result of the diffing is the strings that were added and/or removed from
  the current content. These differences are then applied to the parts,
  @@ -51,7 +51,7 @@ which relate poorly to text input or changes, and don't need the `beforeinput` e
  which isn't broadly supported yet.
  Once the parts of the model are updated, the DOM of the editor is then reconciled
  -with the new model state, see `renderModel` in `render.js` for this.
  +with the new model state, see `renderModel` in `render.ts` for this.
  If the model didn't reject the input and didn't make any additional changes,
  this won't make any changes to the DOM at all, and should thus be fairly efficient.
  