Add global installation instructions for Composer

[kix]

It's quite common for a tool like phpDocumentor to be installed globally.

The existing per-project instructions have been updated, too. Also note that they suggest to use composer require --dev, as this is the most common case of installation, in my opinion.

[drbyte]

For 'exeute' I think you meant 'execute'?

[kix]

@drbyte, is the PR overall good though?

[drbyte]

I was just pointing out the typos so you could address them before the project leads review the PR.

It's debatable whether your changes are too specific to linux/mac, vs also adding stuff for Windows environments is necessary, vs merely adding a link to Composer's site about configuring paths/etc.

But it's not my call at all. I was just being pedantic about typos! LOL

[kix]

@drbyte, well, thanks a lot, anyways (I should've noticed these two stupid typos myself)
By the way, the instructions basically assume a Unix-based environment with composer in PATH anyways, so I think it fits good with the rest of the docs.

[kix]

The build failure is totally unrelated to the subject of this PR.

[mvriel]

Hello @kix,

My apologies for not responding sooner; I have been ill for some time. At this moment I do not think it is wise to document this as this will give a signal that we officially support a global installation with Composer.

Since we are already supporting a fair amount of installation methods and we cannot guarantee that there will be no version conflicts when installing globally it is best to leave this option for advanced users who know how to do it and how to solve any issues that may arise.

I am sorry that this means that I will have to reject your contribution; I hope you understand my reasons for doing so.

With kind regards,

Mike

[kix]

@mvriel, OK, no problem, sure. Although I'd really like to see PHPDocumentor as a globally installable package once.