DOC: fix origin names

MIGRATION.md

@@ -12,21 +12,22 @@ If you have existing clones (and muscle memory), make sure you always use `main`
 ## Migrating development to GitHub:
 
 - [create a fork of github.com/bilby-dev/bilby if you don't already have one](https://github.com/bilby-dev/bilby/fork)
-- if git.ligo.org/lscsoft/bilby is your current origin remove `git remote remove origin`
-- make github the new origin `git remote add origin [email protected]:bilby-dev/bilby.git`
-- add your fork on github as a remote `git remote add mine [email protected]:${ME}/bilby.git`
-- checkout and update `main` `git checkout origin/main && git pull`
+- fetch all upstream changes `git fetch --all && git pull`
+- if git.ligo.org/lscsoft/bilby or a personal fork on git.ligo.org is in your remotes, remove it. Use `git remote -v` to see remotes and `git remote remove` to remove them (they can be added again if needed)
+- add your fork on github as a remote `git remote add origin [email protected]:${ME}/bilby.git` (see, e.g., [here](https://stackoverflow.com/questions/9257533/what-is-the-difference-between-origin-and-upstream-on-github) for remote nomenclature)
+- add the main repo `git remote add upstream [email protected]:bilby-dev/bilby.git`
+- checkout and update `main` `git checkout upstream/main && git pull`
 - checkout the new feature branch `git checkout -b FEATURE-BRANCH-NAME`
-- push your feature branch to your fork `git push --set-upstream mine FEATURE-BRANCH-NAME`
+- push your feature branch to your fork `git push --set-upstream origin FEATURE-BRANCH-NAME`
 
 ## Migrating an MR to GitHub:
 
 This largely follows the above instructions for migrating development.
 
 - [create a fork of github.com/bilby-dev/bilby if you don't already have one](https://github.com/bilby-dev/bilby/fork)
 - checkout your feature branch `git checkout FEATURE-BRANCH-NAME`
-- add your fork on github as a remote `git remote add mine [email protected]:${ME}/bilby.git`
-- push your feature branch to your fork `git push --set-upstream mine FEATURE-BRANCH-NAME`
+- add your fork on github as a remote `git remote add origin [email protected]:${ME}/bilby.git`
+- push your feature branch to your fork `git push --set-upstream origin FEATURE-BRANCH-NAME` (do *not* push to `github.com/bilby-dev/bilby`)
 - open a PR to [github.com/bilby-dev/bilby](https://github.com/bilby-dev/bilby/compare)
 - copy the description and summarise relevant discussion
 - close the MR on [git.ligo.org](https://git.ligo.org/lscsoft/bilby/-/merge_requests)