legalizer documentation

[KA7E]

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Types of changes

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

[vaughnbetz]

Looks good; I have a few suggested changes.

[KA7E]

@vaughnbetz for expedience I went ahead and added default flat placement file name generation (in a separate PR). Please review both that PR and this one when CI completes.

[vaughnbetz]

Looks good. i added one more comment for the --legalize option which should be easy to resolve.

[vaughnbetz]

@KA7E
Please see the comment above and resolve it so we can get this feature in, as it is described & referenced in a Heart paper now.
To merge this documentation, the feature itself needs to work, and the code for that should be added as soon as possible. I believe the remaining items are:

1. Add the code for the actual flat placement file parsing and calls to the cluster creation API to make the clustering.
2. Add a few tests.
3. Make this small documentation update

If there are more updates required please add to this list.