Added SHA1 & SHA256 application certificate fingerprints to README

[DanyPM]

Type of change

• Feature
• Bugfix
• Technical
• Other : README modification

Content

Add the app certificate fingerprint to the README file, enabling apps and users to check the integrity of apk installed from github.

Motivation and context

The main purpose is to enable subsequent verification of the app through AppVerifier, including adding the fingerprint to its internal database.

Screenshots / GIFs

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/tchapgouv/tchap-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/tchapgouv/tchap-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[yostyle]

Thank you for your contribution. That's not the right certificate fingerprint of APKs from github. Please update it.

Github:
Signer #1 certificate SHA-256 digest: 2799b5dc1c4ee23127bffdad325db7096f5d0b4e3856f0000305e23f61f991ac
Signer #1 certificate SHA-1 digest: 48d2a6cb6a779fc8fa3b75cd56a55cc706886205

Google Play Store (your suggestion):
Signer #1 certificate SHA-256 digest: 0d9cc8cbbfac2ba6a46cccd7b2fc2714f0b71830384f4e75f36d3a7e48128d8b
Signer #1 certificate SHA-1 digest: c64612d1b02ac86e98fb7e37965b6d228e4cf6ec

[yostyle]

@DanyPM could you update your PR ?

[DanyPM]

Thank you for the feedback. The PR has been updated.