Add note about non-OSM data to home page

Author: joto

index.html

@@ -15,6 +15,12 @@
 that data in many different ways. They are intended for developers and
 cartographers who want to use OSM data in their own projects.</p>
 
+<p style="color: red;">These tools are meant for OSM data, not for other kinds
+of data that comes in something resembling the OSM data formats. If they don't
+work with non-OSM data, this is not considered a bug. Please don't open a bug
+report unless you are willing to pay money to the developers to fix these
+problems for you.</p>
+
 <div class="major-projects">
         <a class="box" href="/osmium-tool/">
             <img src="/img/logo-osmium-tool.svg" width="32" height="32" alt=""/>