Improve Azure pipelines to skip some changes

[carusogabriel]

We can improve

https://github.com/php/php-src/blob/47e4001976f3ff85a6d479df39dc82d4ceb18b19/azure-pipelines.yml#L7-L12

to skip builds for changes in text-only files :)

[himanshu007-creator]

can i work on this issue?

[nikic]

I'm actually not sure what this issue is suggesting ... doesn't the referenced part of azure-pipelines.yml already skip doc-only changes?

[carusogabriel]

@nikic What I meant was documentation, README.mds in the extensions, etc.

@himanshu007-creator Sure, go ahead!

[himanshu007-creator]

@nikic What I meant was documentation, README.mds in the extensions, etc.

@himanshu007-creator Sure, go ahead!

php/php-src#6876