feat: create gif files and store them in a simple markdown file

[manishraj-003]

Fixes #2875.

Changes

I've created a markdown file(.md) which stores all the gif files used in experiment demonstration.

Screenshots / Recordings

N/A

Checklist:

• [x] No hard coding: I have used values from constants.dart or localization files instead of hard-coded values.
• [x] No end of file edits: No modifications done at end of resource files.
• [x] Code reformatting: I have formatted the code using dart format or the IDE formatter.
• [x] Code analysis: My code passes checks run in flutter analyze and tests run in flutter test.

Summary by Sourcery

Documentation:

• Add a markdown document listing all GIF files used for barometer, channel parameters, and light distance experiment demonstrations.