Release checklist v1.4.0

[rogerkuou]

• Add JOSS badge Add JOSS paper badge to README #123

I will make a new release by preforming the following steps:

• Step1: Update version in pyproject.toml
• Step2: Update docs/CHANGELOG.md with new change information
• Step3: Create release/tag at https://github.com/TUDelftGeodesy/sarxarray/releases

Hint(s):

• Step 1 and 2 can be done semi-automatically by calling agent skill, see the Making a release section in CONTRIBUTING.md. However the changes will always be reviewed and commited by human.