[plugins] Convert to Markdown, normalize section names and URLs

_fc-plugins/report.md

+---
+layout: plugin
+title: Report
+description: Report on status of ACSL annotations
+key: reporting
+distrib_mode: main
+---
+
+## Overview
+
+**Report** is meant to provide a summary of the status (valid, invalid,
+unknown) of ACSL annotations present on the code under analysis. Such
+summary can be provided in different formats: plain text, CSV and JSON.
+For the latter, it is possible to provide a finer classification according
+to some user-provided rules. This is mainly intended to be used in conjunction
+with the [WP](wp.html) plug-in, and is thus documented in
+the [WP manual](/download/frama-c-wp-manual.pdf).
+
+## Usage
+
+Report is part of the main distribution of Frama-C. It is typically
+used after a main analysis, e.g. with:
+
+    frama-c -wp -wp-rte file.c -then -report
+
+which will output something like
+
+```
+...
+[  Valid  ] Instance of 'Pre-condition 'ordered_length'' at call 'lemma_func_count_subset' (file 04-mjrty.c, line 82)
+
+by Wp.typed.
+
+------------------------------------------------------------
+--- Status Report Summary
+------------------------------------------------------------
+136 Completely validated
+300 Considered valid
+436 Total
+------------------------------------------------------------
+```