Fix NOTE for method naming in Ruby and add intro sentence to next section.

[ci skip]

guides/source/testing.md

@@ -204,7 +204,9 @@ end
 
 However only the `test` macro allows a more readable test name. You can still use regular method definitions though.
 
-NOTE: The method name is generated by replacing spaces with underscores. The result does not need to be a valid Ruby identifier though, the name may contain punctuation characters etc. That's because in Ruby technically any string may be a method name. Odd ones need `define_method` and `send` calls, but formally there's no restriction.
+NOTE: The method name is generated by replacing spaces with underscores. The result does not need to be a valid Ruby identifier though, the name may contain punctuation characters etc. That's because in Ruby technically any string may be a method name. This may require use of `define_method` and `send` calls to function properly, but formally there's little restriction on the name.
+
+Next, let's look at our first assertion:
 
 ```ruby
 assert true