Convert the FAQ from FML to Markdown and fix its dead links

modello-maven-plugin/src/site/markdown/faq.md

@@ -0,0 +1,35 @@
+---
+title: Frequently Asked Questions
+---
+
+# Frequently Asked Questions
+
+1. [Where can I find documentation about Modello?](#question1)
+2. [Is Modello really used anywhere?](#question2)
+
+<a name="question1"></a>
+
+### Where can I find documentation about Modello?
+
+The [Modello model descriptor](https://codehaus-plexus.github.io/modello/modello.html) is described and
+documented with Modello.
+
+<a name="question2"></a>
+
+### Is Modello really used anywhere?
+
+Modello is used extensively in Maven. You can find examples of models:
+
+- [Maven's POM](https://maven.apache.org/ref/current/maven-model/maven.html): the mdo file for this model
+  is [`maven.mdo`](https://github.com/apache/maven/blob/master/api/maven-api-model/src/main/mdo/maven.mdo)
+  (Maven 4; the Maven 3 version is on the
+  [`maven-3.9.x` branch](https://github.com/apache/maven/blob/maven-3.9.x/maven-model/src/main/mdo/maven.mdo))
+- [Maven's settings](https://maven.apache.org/ref/current/maven-settings/settings.html): the mdo file for
+  this model is
+  [`settings.mdo`](https://github.com/apache/maven/blob/master/api/maven-api-settings/src/main/mdo/settings.mdo)
+- [Maven assembly plugin](https://maven.apache.org/plugins/maven-assembly-plugin/): uses both an
+  [assembly model](https://github.com/apache/maven-assembly-plugin/blob/master/src/main/mdo/assembly.mdo)
+  and an
+  [assembly component model](https://github.com/apache/maven-assembly-plugin/blob/master/src/main/mdo/assembly-component.mdo)
+- [Doxia site model](https://github.com/apache/maven-doxia-sitetools/blob/master/doxia-site-model/src/main/mdo/site.mdo),
+  the model behind `site.xml`