Fix merging Dockerfile

Dockerfile

-FROM alpine:3.14
-
-RUN apk --no-cache add --update go wget tar \
-    && wget https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/-/archive/v1.1.0/snowflake-v1.1.0.tar.bz2 \
-    && tar xjf snowflake-v1.1.0.tar.bz2 \
-    && cd snowflake-v1.1.0/proxy \
-    && go get && GO111MODULE=on go build -o proxy . \
-    && mv proxy /usr/local/bin/ \
-    && go clean -r -cache -modcache \
-    && cd ../.. \
-    && rm -rf snowflake \
-    && rm snowflake-v1.1.0.tar.bz2 \
-    && apk del go wget tar
+FROM alpine:3.14 AS builder
+RUN apk add --update go git
+WORKDIR /builder
+RUN git clone -b v1.1.0 https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/ 
+WORKDIR /builder/snowflake/proxy
+RUN go get 
+RUN go build -o proxy .
 
-ENTRYPOINT [ "proxy" ]
+FROM alpine:3.14
+COPY --from=builder /builder/snowflake/proxy/proxy /proxy
+ENTRYPOINT [ "/proxy" ]

README.md

-#### To run this docker container:
+## To run this docker container:
 ``` 
 docker-compose up -d
 ```
 
-#### Releasing a new image
+## Releasing a new image
 First, build the image:
 ```
 make build
@@ -22,10 +22,36 @@ git tag -a -s "vVERSION" -m "Docker image version VERSION"
 git push --tags origin main
 ```
 
-#### Adding Custom URLs:
-To add custom URLs before building the image change the URLs in ENTRYPOINT to your desired URLs. Default URLs are shown below.
+## Adding custom options:
+To use custom options when running this image you can add them to `command:` line in the docker-compose.yml like this:
 
-``` dockerfile
-ENTRYPOINT [ "proxy" , "--broker" , "https://snowflake-broker.torproject.net/" , "--relay" , "wss://snowflake.torproject.net/" ]
+    command: [ "-broker" , "https://snowflake-broker.torproject.net/"  ]
 
-```
+so the full docker-compose.yml looks something like this:
+
+    version: "3.8"
+
+    services:
+        snowflake-proxy:
+            network_mode: host
+            image: thetorproject/snowflake-proxy:latest
+            container_name: snowflake-proxy
+            restart: unless-stopped
+            command: [ "-broker" , "https://snowflake-broker.torproject.net/" ]
+
+### Available options:
+
+    -broker string
+            broker URL (default "https://snowflake-broker.bamsoftware.com/")
+    -capacity uint
+            maximum concurrent clients
+    -keep-local-addresses
+            keep local LAN address ICE candidates
+    -log string
+            log filename
+    -relay string
+            websocket relay URL (default "wss://snowflake.bamsoftware.com/")
+    -stun string
+            stun URL (default "stun:stun.stunprotocol.org:3478")
+    -unsafe-logging
+            prevent logs from being scrubbed