upd docs

Author: soulteary

README.md

@@ -1,3 +1,17 @@
 # Nginx Docker Playground
 
 Nginx Development Environment based on official docker image.
+
+## Docker Image Name
+
+`docker pull soulteary/prebuilt-nginx-modules:base-1.21.0`
+
+## Nginx Versions
+Below are other available nginx versions.
+
+- 1.21.0
+- 1.20.0
+- 1.19.10
+- 1.19.9
+- 1.19.8
+- 1.19.7