Allow squash merge in the merge step

[oadultradeepfield]

Description

Following the discussion in git-mastery/exercises#68, it was suggested that the implementation of the merge step in this repository (repo-smith) was initially created to support early exercises and might not be fully complete.

To support the implementation of the exercise T6L2/merge-squash, the merge step in repo-smith should now allow squash merges in addition to the existing fast-forward option.

Changes Made

1. Added a new boolean parameter squash to the MergeStep data class, enabling squash merge functionality alongside the original --no-ff option. When squash is set to True, an additional step is performed to commit the merged changes.
2. Updated the RepoInitializer class to initialize the merge step with the new squash parameter.

[woojiahao]

Could you do a bump on the version in pyproject.toml? This would be a minor release. I'll publish once this is merged. Thank you!

I will likely be updating the CI to autopublish when a tagged release is made, but for now, we need to manually bump the dependency

[woojiahao]

Thank you!

[woojiahao]

@oadultradeepfield the version has been published, could you run pip install -r requirements.txt -U --no-cache-dir in the exercises repository and verify that version 0.11.0 is installed? That should contain your fix

[oadultradeepfield]

@oadultradeepfield the version has been published, could you run pip install -r requirements.txt -U --no-cache-dir in the exercises repository and verify that version 0.11.0 is installed? That should contain your fix

@woojiahao Yes, the current version is now 0.11.0. Thanks!