Add proper parsing/stripping of comments around docs frontmatter (#8372)

* Quick fix to main docs page

* Strip frontmatter comments

* Fix for main README

DOCUMENTATION.md

@@ -1,10 +1,3 @@
-<!--
----
-title: "Netdata Documentation"
-custom_edit_url: https://github.com/netdata/netdata/edit/master/DOCUMENTATION.md
----
--->
-
 # Netdata Documentation
 
 **Netdata is real-time health monitoring and performance troubleshooting for systems and applications.** It helps you

README.md

@@ -1,6 +1,6 @@
 <!--
 ---
-title: "Netdata [![Build Status](https://travis-ci.com/netdata/netdata.svg?branch=master)](https://travis-ci.com/netdata/netdata) [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/2231/badge)](https://bestpractices.coreinfrastructure.org/projects/2231) [![License: GPL v3+](https://img.shields.io/badge/License-GPL%20v3%2B-blue.svg)](https://www.gnu.org/licenses/gpl-3.0) [![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Freadme&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)](<>)"
+title: "Netdata"
 custom_edit_url: https://github.com/netdata/netdata/edit/master/README.md
 ---
 -->

docs/generator/buildhtml.sh

@@ -33,6 +33,9 @@ cp -a ./${GENERATOR_DIR}/custom ./${SRC_DIR}/
 echo "Modifying README header"
 sed -i -e '0,/# Netdata /s//# Netdata Documentation\n\n/' ${SRC_DIR}/README.md
 
+# Strip comments around frontmatter.
+find ${SRC_DIR} -name '*.md' -exec sed -i "/<!--/d;/-->/d;" {} \;
+
 # Remove all GA tracking code
 find ${SRC_DIR} -name "*.md" -print0 | xargs -0 sed -i -e 's/\[!\[analytics.*UA-64295674-3)\]()//g'