Update comments.

README.md

@@ -78,6 +78,7 @@ but rather read the examples or the tests.
 In this documentation, 'shall' will be used to indicate a user constraint that is
 mandatory to follow under penalty of undefined behavior.
 'should' will be used to indicate a recommendation to the user.
+All pointers expect non-null argument except if indicated.
 
 Components
 ----------

m-core.h

@@ -113,7 +113,7 @@
  * dialect. It is expected as M*LIB is a C library.
  *
  * * For clang, the generated functions may not be always used,
- * and CLANG failed to relalize it.
+ * and CLANG failed to realize it.
  * See https://bugs.llvm.org//show_bug.cgi?id=22712
  *
  * * A manualy created buffer is given to fscanf. It is needed