Make opening URLs not fatal if a web browser cannot be opened from the terminal

[nelsonjchen]

Proposed changes

This is useful for environments where a launching a Desktop web browser from the terminal is unavailable or inaccessible.

For me, that would WSL out of the box on Windows. A similar pattern can be seen in Google CLIs.

Closes #89

Types of changes

• [ ] Bugfix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Refactor (changes to code, which do not change application behavior)

Checklist

• [x] I have filled out this PR template
• [x] I have read the CONTRIBUTING doc
• [ ] I have added automated tests that prove my fix is effective or that my feature works
• [X] I have added necessary documentation (README.md, inline comments, etc.)
• [X] I have updated the CHANGELOG.md under a ## next release, with a short summary of my changes

Relevant Links

Closes #89

Further comments

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