verbiage about "make check"

README

@@ -78,7 +78,10 @@ FLAC uses autoconf and libtool for configuring and building.
 Better documentation for these will be forthcoming, but in
 general, this should work:
 
-./configure && make && make install
+./configure && make && make check && make install
+
+The 'make check' step is optional; omit it to skip all the tests,
+which can take several hours.
 
 NOTE: Despite our best efforts it's entirely possible to have
 problems when using older versions of autoconf, automake, or