Bump signpath/github-action-submit-signing-request from 2.2 to 2.3

Bumps [signpath/github-action-submit-signing-request](https://github.com/signpath/github-action-submit-signing-request) from 2.2 to 2.3.
- [Release notes](https://github.com/signpath/github-action-submit-signing-request/releases)
- [Commits](https://github.com/signpath/github-action-submit-signing-request/compare/v2.2...v2.3)

---
updated-dependencies:
- dependency-name: signpath/github-action-submit-signing-request
  dependency-version: '2.3'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/package-windows.yml

@@ -58,7 +58,7 @@ jobs:
           name: windows-build-${{ matrix.entry }}
           path: dist/*.exe
       - id: optional_step_id
-        uses: signpath/github-action-submit-signing-request@v2.2
+        uses: signpath/github-action-submit-signing-request@v2.3
         if: ${{ github.repository == 'ciromattia/kcc' }}
         with:
          api-token: '${{ secrets.SIGNPATH_API_TOKEN }}'

.github/workflows/package-windows7.yml

@@ -51,7 +51,7 @@ jobs:
           name: windows7-build
           path: dist/*.exe
       - id: optional_step_id
-        uses: signpath/github-action-submit-signing-request@v2.2
+        uses: signpath/github-action-submit-signing-request@v2.3
         if: ${{ github.repository == 'ciromattia/kcc' }}
         with:
          api-token: '${{ secrets.SIGNPATH_API_TOKEN }}'

README.md

@@ -148,6 +148,8 @@ You'll need to install various tools to access important but optional features.
 
 ### KindleGen
 
+(This is not needed for Koreader users on jailbroken Kindle. Just set output to CBZ instead.)
+
 On Windows and macOS, install [Kindle Previewer](https://www.amazon.com/Kindle-Previewer/b?ie=UTF8&node=21381691011) and `kindlegen` will be autodetected from it.
 
 If you have issues detecting it, get stuck on the MOBI conversion step, or use Linux AppImage or Flatpak, refer to the wiki: https://github.com/ciromattia/kcc/wiki/Installation#kindlegen