Stop calling the upstack push a force-push in the README (#41)

The "How it works" list described step 5 as force-pushing updated
branches. There is no force push in the action: the synthetic merge
commit is built as a descendant of the child's old head precisely so the
push is a fast-forward (which keeps the PR mergeable and the
`synchronize` resume firing). Dropped the word "force".

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_Generated by [Claude
Code](https://claude.ai/code/session_01CCzKo3mz5W9vSZSiqgmDky)_

Co-authored-by: Claude <noreply@anthropic.com>

Author: Phlogistique

README.md

@@ -20,7 +20,7 @@ This action tries to fix that in a transparent way. Install it, and hopefully th
 2. Finds PRs that were based on the merged branch (direct children only)
 3. Creates a synthetic merge commit with three parents (child tip, deleted branch tip, squash commit) to preserve history without re-introducing code
 4. Updates the direct child PRs to base on trunk now that the bottom change has landed
-5. Force-pushes updated branches and deletes the merged branch
+5. Pushes updated branches and deletes the merged branch
 
 **Note:** Indirect descendants (grandchildren, etc.) are intentionally not modified. Their PR diffs remain correct because the merge-base calculation still works—the synthetic merge commit includes the original parent commit as an ancestor. When their direct parent is eventually merged, they become direct children and get updated at that point.