Update README.md to use dart pub instead of pub

[julemand101]

The pub command no longer exist and users are therefore required to use dart pub instead for installation.

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[elliette]

Thanks! The failing release reminder test should be fixed by merging this branch with master

[julemand101]

Hope I done the pull correctly and everything is okay now.

[elliette]

Thank you! LGTM

[auto-submit]

auto label is removed for dart-lang/webdev/2195, due to This PR has not met approval requirements for merging. You are not a member of dart-team and need 1 more review(s) in order to merge this PR.

• Merge guidelines: You need at least one approved review if you are already part of flutter-hackers or two member reviews if you are not a flutter-hacker before re-applying the autosubmit label. Reviewers: If you left a comment approving, please use the "approve" review action instead.

[julemand101]

@elliette Do you know why this pull-request have yet to be merged? It does not really have any kind of deadline but I just find it weird it just stays in this state like it is waiting for something?

[elliette]

auto label is removed for dart-lang/webdev/2195, due to This PR has not met approval requirements for merging. You are not a member of dart-team and need 1 more review(s) in order to merge this PR.

You will need to merge it manually (with the Squash and merge button) - if you don't see it, I can merge it for you.

[julemand101]

Well, I don't have that button so you are allowed to do so for me :)
Guess it is because I am not part of the project?