chore(docs): Correct name of Postgres "peer" authentication method

[hongquan]

Fixes #

Short description of what this resolves:

I incorrectly called Postgres "peer" authentication method as "ident". This PR is to fix that.

Changes proposed in this pull request:

• Change "ident" to "peer" in installation doc.

Checklist

• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.
• The unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

• All the functions created/modified in this PR contain relevant docstrings.

[codecov]

Codecov Report

Merging #7381 into development will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           development    #7381   +/-   ##
============================================
  Coverage        64.24%   64.24%           
============================================
  Files              259      259           
  Lines            13136    13136           
============================================
  Hits              8439     8439           
  Misses            4697     4697           

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