move the build prequisites in a designated space

[paull39]

Hey,

its a more of a bigger overhaul.
I've been through the process of setting up a Thunderbird repository twice and stumbled upon the prerequisites.

Here are my main changes:

• there is a new point in the main summary called "Prerequisites for the build".
• a short summay in the next section which should work as a small checklist

My reasoning behind the change:

• macOS, linux and windows leaves the space of a "wizard" style, clicking next
• giving a short summary in the build what you should have done before to reduce the confusion that we left the space of a wizard style
• it's the most broad topic for building and deserves to be an extra point to reduce confusion
• although i like it to be called "Building Prerequisites" its more eye candy if it starts with Prerequisites because in the summary Building Thunderbird follows

[jfx2006]

feedback+ from me. Thanks!

[jobisoft]

@paull39 : Are you able to resolve the conflicts? Otherwise I could merge these changes manually, but the information that you contributed them would be lost.

[paull39]

@jobisoft Hey I'm unsure if the This page has moved will work. Do you think it's possible to get a preview to see if everything is correct?

[jobisoft]

For larger changes it is better to do them in gitbook directly. Should I create an account for you?

I cannot preview pull requests.