fix(find): Fallback to `fd` if `fdfind` not found

[aidenlangley]

For the benefit of other distros that have fd installed.

Closes #53

I have only tested the functionality that I know to test, searching for files, math & opening applications - asked for some guidance in Pop Mattermost dev channel to thoroughly test.

[aidenlangley]

[mmstick]

The devcontainer changes should either be in a separate PR, or this PR should contain two commits with the descriptions of

• chore: Add VS Code devcontainer
• fix(find): Fallback to `fd` if `fdfind` not found