mainpage.dox: Remove reference to LREADME.
This reference no longer exists and was not particularly useful either.
Before this fix, following warning was generated during 'make':
avm/mainpage.dox:20: warning: unable to resolve reference to 'LREADME'
for \ref command
diff --git a/mainpage.dox b/mainpage.dox
index 10924ac..3ec26e6 100644
--- a/mainpage.dox
+++ b/mainpage.dox
@@ -21,11 +21,7 @@
\subsection main_startpoints Starting Points
- Consult the \ref changelog for a complete list of improvements in this
release.
- \if av1_md_support
- - [README](\ref LREADME) contains instructions on compiling the sample applications.
- \else
- \ref readme contains instructions on compiling the sample applications.
- \endif
- Read the \ref usage "usage" for a narrative on codec usage.
- Read the \ref samples "sample code" for examples of how to interact with the
codec.
