docs: add go.17+ install instructions (#1280)

Add go 1.17+ install intructions, `go get` has been deprecated
from go 1.17 and onwards as an install method.

Author: lopezator

docs/overview/install.md

@@ -14,12 +14,20 @@ brew install sqlc
 sudo snap install sqlc
 ```
 
-## go install
+## go install 
+
+### Go >= 1.17:
 
 ```
 go install github.com/kyleconroy/sqlc/cmd/sqlc@latest
 ```
 
+### Go < 1.17:
+
+```
+go get github.com/kyleconroy/sqlc/cmd/sqlc
+```
+
 ## Docker
 
 ```