Update plugins doc with the correct _SKIP_DEPLOY ENV vars

[PhillypHenning]

Description

Updated to support the skip_deployment configuration option that was added to all major supported plugins.

Type of change

• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation

[arm4b]

Cross-linking with

• Adding skip-deploy bitops configuration option bitops-plugins/terraform#13
• Adding skip-deploy bitops configuration option bitops-plugins/ansible#3
• Adding skip-deploy bitops configuration option bitops-plugins/helm#13
• Adding skip-deploy bitops configuration option bitops-plugins/cloudformation#7

Based on what we've seen there are lots of documentation misses and outdated things here and there.

It's nice to see the _SKIP_DEPLOY consistency across the board and all the places: plugins + Readmes + docs 👍