Add pinch-to-zoom support while editing notes

### ⚠️ This issue respects the following points: ⚠️

- [x] This is a **enhancement/feature request**. Not a [bug or question](https://github.com/gsantner/markor/issues/new/choose).
- [x] The topic is **not** already reported at [Issues](https://github.com/gsantner/markor/issues?q=#js-issues-search). _(I've searched it)_.
- [x] Markor **is** up to date. See [Releases](https://github.com/gsantner/markor/tags) for the latest version. Updates are available from [F-Droid](https://f-droid.org/en/packages/net.gsantner.markor/) and GitHub.
- [x] The wanted feature/enhancement is not present in the latest development version (git master). (Please [download](https://nightly.link/gsantner/markor/workflows/build-android-project/master) and try the test version of Markor, named **Marder**. Don't worry; Markor and Marder appear as completely separate applications. You can install both side-by-side, and Markor's settings are not touched. If your desired feature is present, you don't need to open this issue. The change will be part of the next Markor update.)

### Description

Title:
Add pinch-to-zoom support while editing notes

Description:

Please add pinch-to-zoom support inside the editor while editing notes.

Currently, when editing small text or dense content, it can become difficult to read or precisely modify text. It would be very useful if users could temporarily zoom in/out using pinch gestures directly inside the editor.

Requested behavior:

- Allow pinch-to-zoom while editing notes.
- Zoom should only affect the visual editing view and should not permanently change document font size.
- Useful for:
- Editing small text
- Precise cursor placement
- Reading dense markdown or code blocks
- Temporary closer view during editing

Expected behavior:

- Similar to zooming while editing in Samsung Notes and other note-taking apps.
- Optional: remember zoom level per session or per note.

This feature would improve accessibility and editing comfort, especially on smaller screens.

if possible this function required in general for editing anything in this app.

### Information

Android version: Android 13
Device: Samsung Galaxy F62 (SM-E625F)
App Version: 2.16.1

### Source

GitHub Releases

### Format / File type

Not specific

### Additional info / Log

```shell
-This request is mainly about improving the editing experience for users working with compact text, markdown formatting, code blocks, or large notes on mobile devices.
```

Start by locating Markor's note editor implementation and checking how it currently handles text sizing and touch gestures. Reproduce editing on Android 13 with dense text, then define completion as temporary pinch-to-zoom in the editing view without permanently changing the document's font size.

Written by the indexing model from the issue text.