[DOC] Plugin installation page should describe the security posture of installed plugins

[peternied]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.
There should be text of some kind on the documentation site that helps OpenSearch users / operators understand the implications of what plugins can do

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.