Add links to external references

addons/cert.py

@@ -3,6 +3,7 @@
 # Cert: Some extra CERT checkers
 #
 # Cppcheck itself handles many CERT rules. Cppcheck warns when there is undefined behaviour.
+# CERT Homepage: https://www.cert.org/secure-coding/
 #
 # Example usage of this addon (scan a sourcefile main.cpp)
 # cppcheck --dump main.cpp

addons/misra.py

@@ -10,6 +10,8 @@
 # Limitations: This addon is released as open source. Rule texts can't be freely
 # distributed. https://www.misra.org.uk/forum/viewtopic.php?f=56&t=1189
 #
+# The MISRA standard documents may be obtained from https://www.misra.org.uk
+#
 # Total number of rules: 153
 
 import cppcheckdata