Make it more clear in README that what makes up a substantial change …

…is not set in stone

README.md

@@ -17,7 +17,7 @@ RFCs have four stages:
 
 ## When to follow this process
 
-You should create an RFC if you want to make a substantial change to the Boa ecosystem. This is not set in stone, and evolves with community norms. Substantial changes include, but is not limited to:
+You should create an RFC if you want to make a substantial change to the Boa ecosystem. Substantial changes include, but is not limited to:
 
 - Semantic or syntactic change to the language that is not a bugfix.
 - Removing a feature.
@@ -34,6 +34,8 @@ Some changes do not require an RFC:
 - Additions that are invisible to end users of Boa.
 - Bug fixes
 
+These are not set in stone, and evolve with community norms.
+
 ## The process
 
 Note: Your RFC will be licensed under the MIT license, found in the `LICENSE` file. If you are uncomfortable with this, you may turn around now.