Direct user to follow the upgrade steps after installation

[agmckee]

As discussed on the community forums, the appstarter doesn't work out of the box after a fresh installation. This was determined to be due to the composer.lock file being out of date, running composer update installs the up to date version of the framework.

Description
Updated the installation via Composer documentation to direct users to follow the steps in the "Upgrading" section even after a fresh installation. This ensures the framework is up to date.

Checklist:

• Securely signed commits
• Component(s) with PHPdocs: N/A
• Unit testing, with >80% coverage: N/A
• User guide updated
• Conforms to style guide: N/A

[jim-parry]

Oooh - you may have hit the nail on the head ... the appstarter ships with a composer.lock file that it shouldn't! Let me play with that ... this PR might not be needed if the problem can be fixed at the root :)

[jim-parry]

composer.lock is git ignored, and I don't know how it got into the repo :(
I have deleted it, and re-created the beta.3 release, but it still shows up with alpha.4 and needs updating :(
I am going to leave your comment in the installation instructions, and try to figure out this puzzle later.
Thanks!

[MGatner]

@jim-parry Sorry if this is a dumb question, but did you remove the file or clean it from the history? .gitignore has weird interactions with files already committed and git rm.

[jim-parry]

Good question. I probably didn't do it right, and need to fix it :(