Update g_stands_for

doc/g_stands_for.md

@@ -1,18 +1,15 @@
-Each version of gRPC gets a new description of what the 'g' stands for, since
-we've never really been able to figure it out.
+'g' stands for something different every gRPC release:
 
-Below is a list of already-used definitions (that should not be repeated in the
-future), and the corresponding version numbers that used them:
-
-- 1.0 'g' stands for 'gRPC'
-- 1.1 'g' stands for 'good'
-- 1.2 'g' stands for 'green'
-- 1.3 'g' stands for 'gentle'
-- 1.4 'g' stands for 'gregarious'
-- 1.6 'g' stands for 'garcia'
-- 1.7 'g' stands for 'gambit'
-- 1.8 'g' stands for 'generous'
-- 1.9 'g' stands for 'glossy'
-- 1.10 'g' stands for 'glamorous'
-- 1.11 'g' stands for 'gorgeous'
-- 1.12 'g' stands for 'glorious'
+- 1.0 'g' stands for ['gRPC'](https://github.com/grpc/grpc/tree/v1.0.x)
+- 1.1 'g' stands for ['good'](https://github.com/grpc/grpc/tree/v1.1.x)
+- 1.2 'g' stands for ['green'](https://github.com/grpc/grpc/tree/v1.2.x)
+- 1.3 'g' stands for ['gentle'](https://github.com/grpc/grpc/tree/v1.3.x)
+- 1.4 'g' stands for ['gregarious'](https://github.com/grpc/grpc/tree/v1.4.x)
+- 1.6 'g' stands for ['garcia'](https://github.com/grpc/grpc/tree/v1.6.x)
+- 1.7 'g' stands for ['gambit'](https://github.com/grpc/grpc/tree/v1.7.x)
+- 1.8 'g' stands for ['generous'](https://github.com/grpc/grpc/tree/v1.8.x)
+- 1.9 'g' stands for ['glossy'](https://github.com/grpc/grpc/tree/v1.9.x)
+- 1.10 'g' stands for ['glamorous'](https://github.com/grpc/grpc/tree/v1.10.x)
+- 1.11 'g' stands for ['gorgeous'](https://github.com/grpc/grpc/tree/v1.11.x)
+- 1.12 'g' stands for ['glorious'](https://github.com/grpc/grpc/tree/v1.12.x)
+- 1.13 'g' stands for ['gloriosa'](https://github.com/grpc/grpc/tree/master)