add README

README.md

@@ -0,0 +1,22 @@
+Authenticating Reverse Proxy
+============================
+
+This is a simple reverse proxy that can be used to expose a
+service using HTTP Basic authentication and GitHub Personal Access Tokens as an auth backend.
+
+Other auth methods may be supported in the future.
+
+The org token parameter is optional, but without it, only users who have their org membership publicly visible will be
+able to login.
+
+Usage:
+
+```shell
+docker run -it -e TARGET=http://example.com \
+    -e AUTH_METHOD=GH_BASIC \
+    -e GH_ORG=your-org \
+    -e GH_ORG_TOKEN=ghp_XXXXX \
+    -e BIND=0.0.0.0:8080 \
+    -p 8080:8080 \
+    ghcr.io/richardstephens/authenticating-reverse-proxy:latest
+```