Add REST sample for listing and getting models (#421)

* Add REST sample for listing and getting models - skeleton

* formatting

Change-Id: Id37a33e23349acb5c4d787015a65330f6c96078d

* move to samples/rest (to match cookbook layout)

Change-Id: Ib1ec6500da407342c01da18f3f166dae199a6347

---------

Co-authored-by: Mark Daoust <[email protected]>

Author: shilpakancharla

samples/rest/models.sh

@@ -0,0 +1,11 @@
+set -eu
+
+echo "[START models_list]"
+# [START models_list]
+curl https://generativelanguage.googleapis.com/v1beta/models?key=$GOOGLE_API_KEY
+# [END models_list]
+
+echo "[START models_get]"
+# [START models_get]
+curl https://generativelanguage.googleapis.com/v1beta/models/gemini-pro?key=$GOOGLE_API_KEY
+# [END models_get]