FINERACT-2170: improve asciidoc: clean URIs, more (#4271)

* disable broken fineract-client API asciidoc include
  * this has a side effect of removing ~1,200 pages from the PDF
* remove duplicated/outdated text, reduce sources of truth
  * link to current FAQ
  * introduction is all references now... it was way out of date and also needed formatting fixes
* unset `show-link-uri` to improve PDF rendering
* remove unnecessary/unused `.asciidoctorconfig` file

build.gradle

@@ -249,7 +249,6 @@ allprojects  {
             '**/licenses/**',
             '**/*.md',
             '**/*.adoc',
-            '**/.asciidoctorconfig',
             '**/*.puml',
             '**/*.github/**',
             '**/MANIFEST.MF',