What this PR does / why we need it:

• The Makefile for the installer stopped working after pull request Quick fix for #7864 (Simple search of most metadata fields broken) #7865 was merged.
• The dev guide has a curl step that won't work due to a missing file.
• The README for the Makefile is a bit out of date.

Which issue(s) this PR closes:

Closes #7891

Special notes for your reviewer:

None.

Suggestions on how to test this:

• Ensure you can make the installer.
• Review doc changes.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

No.

Is there a release notes update needed for this change?:

I don't think so. This is mostly inside baseball. ⚾

Additional documentation:

None.