Doc: Clarify what `Inc.` and `Exc.` mean in the table

[LordSimal]

I was not able to find a documentation which explains the difference between Inc. and Exc.

This run was generated without profiling internal PHP methods, therefore it can't really be "including/exlcuding internal functions"

[LordSimal]

My guess would be the difference between:

• including called functions (aka "sub-calls") and their time (or memory) spent and
• excluding called functions

But is that correct? Can we maybe add a simple example to the doc which ilustrates this?

[NoiseByNorthwest]

That is correct.