Clarify why double-quoted strings are sensible.
|@@ -606,7 +606,7 @@|
|- Try not to mix up single-quoted and double-quoted strings within a file:|
|it can make the code harder to read. *Definitely* don't mix up single-quoted|
|and double-quoted strings within a method. If in doubt, use double-quoted|
|+ strings, because you’ll probably need to use interpolation somewhere.|
|- Avoid using `String#+` when you need to construct large data chunks.|
|Instead, use `String#<<`. Concatenation mutates the string instance|