fix strategy of AsciiDocAPI Search for the asciidoc command file:

[jujumo]

also search for sibling files before for system wide path.

[elextr]

Havn't tested but looks ok to me, @MasterOdin any comments?

@jujumo whilst I normally like a good argument about coding styles and especially something as contentious as "else considered harmful" for this just keeping the same style as the rest of the project is more important. Thanks for your understanding. BTW don't make a new PR for each change, just push correcting commits, we can squash them on merge.

If its suggested that the whole project style is to be changed then a separate issue just addressing that should be raised so that it can be discussed first, and (if its decided to go ahead) a suitable implementation strategy formulated (probably for progressive small changes).

[jujumo]

Thanks for your review and your patience. that is my first PR. Next time, I'll manage to make correcting commits.

[aerostitch]

I put 2 suggestions based on @MasterOdin's comment but it looks good to me.