Update Go version info on building page (#2304)

website/content/docs/oss/developing/building.mdx

@@ -8,7 +8,10 @@ description: Building Boundary
 
 Building Boundary from source requires:
 
-- [Go](https://golang.org/dl/) 1.14 or greater. (Note that HashiCorp currently develops against Go 1.15.)
+- [Go](https://golang.org/dl/). Boundary developers keep current with new
+  releases of Go in order to take advantage of new features and to ensure that
+  security issues within Go are addressed. If building Boundary yourself, always
+  use the latest version and keep current.
 - `make` installed
 - [Docker](https://docs.docker.com/get-docker/) installed
 - Basic development environment (git, xcode if you're on Mac, etc)