Document get-key-blocking optional args

Author: zachallaun

docs/2-terminals.markdown

@@ -164,6 +164,16 @@ one if there's none already buffered) you can use `get-key-blocking`:
     ;
     ; => \a
 
+`get-key-blocking` optionally accepts a check interval or timeout:
+
+    :::clojure
+    (t/get-key-blocking term :interval 100 :timeout 5000)
+    ;
+    ; Key presses will be checked for every 100 msecs. If you wait
+    ; 5 seconds, nil will be returned.
+    ;
+    ; => nil
+
 Normal alphanumeric keys are returned as simple Character objects like `\a`.
 
 Note that there's no special attribute to determine if the Shift key was