Update doc

README.md

@@ -54,7 +54,7 @@ Otherwise you may have a noticeable slow-down (up to a factor x10 in some cases)
 M\*LIB is distributed under BSD-2 simplified license.
 
 It is strongly advised not to read the source to know how to use the library
-but rather read the examples.
+but rather read the examples or the tests.
 
 Components
 ----------
@@ -232,7 +232,7 @@ When using M\*LIB, sometimes (often) the list of errors/warnings generated by th
 even if the error itself is minor. This is more or less the same as the use of template in C++.
 You should focus mainly on the first reported error/warning
 even if the link between what the compiler said and what the error is is not immediate:
-for example, a lack of inclusion of an header, an unkown oplist, a missing argument, a missing method in an oplist, ...
+for example, a lack of inclusion of an header, an unkown oplist, a missing argument, a missing method in an oplist, ... Another way to debug is to generate the preprocessed file (by usuallt calling the compiler with the '-E' option instead of '-c') and check what's wrong in the preprocessed file.
 
 The final goal of the library is to be able to write code like this in pure C while keeping type safety and compile time name resolution: