[Enhancement] Change tranformer configuration inside formatted file

[gohierf]

It would be nice to be able to change the transformer configuration from a comment in the file.

For instance, for some test case I want a different alignment width than the default I could use.

*** TestCases ***  # robotidy: configAlignKeywordsSection:widths=10
My First Test
    No Operation

# robotidy: configAlignKeywordsSection:widths=20
My Second Test
    No Operation

My Third Test
    No Operation