Hey guys,

I've converted confluence docs asciidoc [1] [2] ones that will be part of WildFly codebase,
take a look at them and let me know if there are any big issues.

full version:

as most of you already know, I was working on moving our confluence based [1] documentation to asciidoc based one.

result can be seen at [7] or rendered to html at [8]

A good side effect of conversion is that now docs are also browsable directly on GitHub.
For example [2] or [3] 

Currently I kept same structure as we had in confluence, which in practice means
we have set of "guides" that than have lots of sub pages / includes that produce "big" guides.
Currently such guides are:
- Admin Guide
- Developer Guide
- Getting started guide
- Getting Started Developing Applications Guide
- High Availability Guide
- Extending WildFly guide
- JavaEE 7(6 actually) Tutorial
- Elytron security guide
- quickstarts
- Testsuite

Problem is that some of this guide as such make sense, but not all of them do.
In some cases we have duplicated docs for same thing, in others we content in wrong segment.
For example instead of having all subsystem reference docs under admin guide,
some are under Developer Guide and some even under HA guide.

Going forward we should "refactor" docs a bit, so we would end up with 3-4 high quality guides.
We should also go trough all docs and remove/update the outdated content.

Plan is also to have documentation now part of WildFly codebase.
So when we would submit PR with new feature, it would also include documentation for it as well.

Rendered docs can be build as part of our build / release process and can be rendered to different formats.
for example default is HTML [5] or PDF [6]

I've send experimental PR to show how docs would fit into WildFly build [4]

Please take look at current docs and if you have any comments / suggestions what we can improve before merging it let me know.
At this point I've not done much content-wise changes but just conversion + formatting ones. 
Content updates can come after this is merged.


[1] https://docs.jboss.org/author/display/WFLY/Documentation
[2] https://github.com/ctomc/docs-playground/blob/master/admin-guide/Operating_modes.adoc
[3] https://github.com/ctomc/docs-playground/blob/master/developer-guide/EJB3_Reference_Guide.adoc
[4] https://github.com/wildfly/wildfly/pull/10523
[5] https://ctomc.github.io/docs-playground/Admin_Guide.html
[6] https://ctomc.github.io/docs-playground/Admin_Guide.pdf
[7] https://github.com/ctomc/docs-playground
[8] https://ctomc.github.io/docs-playground/