STYLE.md: Add a note on ordering of types

Types should be declared before their first. Let's document this in our
style guide.

1 files changed, 6 insertions, 0 deletions

diff --git a/STYLE.md b/STYLE.md
index bf2dae5dd..0d0beece0 100644
--- a/STYLE.md
+++ b/STYLE.md
@@ -52,6 +52,12 @@ variables.
 In Gitaly we don't use this feature. If the function returns one or
 more values, then always pass them to `return`.
 
+## Ordering
+
+### Declare types before their first use
+
+A type should be declared before its first use.
+
 ## Tests
 
 ### Table-driven tests