Initial code drop

[unixorn]

• Add github actions
• Add 1password-op.plugin.zsh which loads op's completions if the op command is found and they haven't already been defined.

[github-actions[bot]]

MegaLinter status: :warning: WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ ACTION	actionlint	2		0	0.01s
✅ COPYPASTE	jscpd	yes		no	1.02s
✅ CREDENTIALS	secretlint	yes		no	0.86s
✅ GIT	git_diff	yes		no	0.01s
✅ MARKDOWN	markdownlint	1		0	0.31s
✅ MARKDOWN	markdown-link-check	1		0	1.09s
✅ MARKDOWN	markdown-table-formatter	1		0	0.27s
✅ SPELL	misspell	4		0	0.04s
:warning: YAML	prettier	3		1	1.03s
✅ YAML	v8r	3		0	2.14s

See errors details in artifact MegaLinter reports on CI Job page _Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff_