feat(docs): add docs for env vars with github secrets

[yjose]

What does this do?

Add documentation for environment variables when using GitHub Actions, in case you do not want to push environment files.

Why did you do this?

more clarity

Who/what does this impact?

NA

How did you test this?

NA

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[github-actions]

💯 Test Coverage

Lines	Statements	Branches	Functions
	38.85% (183/471)	34.09% (75/220)	25.27% (46/182)

😎 Tests Results

Tests	Skipped	Failures	Errors	Time
40	0 💤	0 ❌	0 🔥	26.136s ⏱️

👀 Tests Details • (40%)

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	38.85	34.09	25.27	40.04

report-only-changed-files is enabled. No files were changed in this commit :)