Add valid8j entry to powered-by-asciidoclet.adoc (#136)

* Move the valid8j entry to existing "powered-by-asciidoclet.adoc" file
* Move valid8j entry to a correct file
- Add an entry to correct .adoc file.
- Remove incorrect .adoc file.
- Correct a link in README.adoc.

---------

Co-authored-by: Hiroshi Ukai <dakusui@gamil.com>

README.adoc

@@ -294,7 +294,7 @@ If you have questions or would like to help develop this project, please join th
 ifndef::env-site[]
 == Powered by Asciidoclet
 
-We have a <<src/docs/asciidoc/asciidoclet-powered.adoc#,Powered by Asciidoclet>> page.
+We have a <<docs/modules/project/pages/powered-by-asciidoclet.adoc#_projects_powered_by_asciidoclet,Powered by Asciidoclet>> page.
 If you have an example of nifty JavaDoc powered by Asciidoclet, please send us a pull request.
 endif::[]
 

docs/modules/project/pages/powered-by-asciidoclet.adoc

@@ -1,3 +1,4 @@
+[#_projects_powered_by_asciidoclet]
 = Projects Powered by Asciidoclet
 
 [cols="2,3,4"]
@@ -28,6 +29,10 @@
 |https://github.com/chrisvest/stormpot[stormpot]
 |http://chrisvest.github.io/stormpot/site/apidocs/stormpot/package-summary.html[JavaDoc]
 
+|https://valid8j.github.io/valid8j/[Stormpot]
+|https://github.com/valid8j/valid8j[valid8j]
+|https://valid8j.github.io/valid8j/apidocs/overview-summary.html[JavaDoc]
+
 |===
 
 TIP: Have a cool Asciidoclet-powered project? Edit this file and send us a pull request.