Fix for #104 (test on bpftool-btf.rst)

[rameezrehman408]

I believe this is a fix for issue#104.

Only 1 sample file is modified (bpftool-btf.rst), to check if it'll be stable.
I am working on setting up the environment to review the docs pages locally. Any guidance in this matter is very welcome.

[qmonnet]

Any guidance in this matter is very welcome.

make -C docs (or make -C tools/bpf/bpftool doc in the kernel repo) will generate the man pages (.8) from the RST files (.rst), using rst2man. Then you can open the page with man directly.

rst2man comes with docutils (python3-docutils on Ubuntu, for example).

One-liner:

$ rst2man docs/bpftool-btf.rst | man -l -

We want the man pages to render the same, ideally we want the code for the man pages (.8) to remain identical.

Note that the final version of the patches will need to be submitted to the BPF mailing list (I can help).

[qmonnet]

The examples won't need to be changed, we need some indent under the :: marking the pre-formatting block, otherwise Docutils cannot know when the block ends.

[rameezrehman408]

Noted.
Skipping the examples.