feat(app): allow zero padding

[SarjuHansaliya]

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The commit message follows our guidelines: https://github.com/riccardoperra/codeimage/blob/main/CONTRIBUTING.md#commit
• [ ] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

• Currently it does not allow padding to be ZERO.

Issue Number: #623

What is the new behavior?

• This PR add change to allow padding to be ZERO.
• Padding UI is changed from Segment control to Select component.

Does this PR introduce a breaking change?

[ ] Yes
[x] No