Add basic usage to documentation

README.md

@@ -1,3 +1,45 @@
 # Phive
 
 Simple, multistage Alpine based phive.io container. Updated monthly
+
+## Usage
+
+
+## As single temporary container 
+```bash
+docker run \
+  --interactive \
+  --tty \
+  --rm \
+  --volume $(pwd):/repo \
+  --workdir=/repo \
+  hyperized/phive \
+  phive install
+
+# One-liner
+docker run -it --rm -v $(pwd):/repo -w /repo hyperized/phive phive install
+```
+
+## As docker-compose service
+```yaml
+version: "3"
+services:
+  phive:
+    image: hyperized/phive:latest
+    restart: 'no'
+    volumes:
+      - ./:/repo
+      - phive:/root/.phive
+    working_dir: /repo
+    entrypoint: ["phive"]
+
+volumes:
+  phive:
+```
+
+Run it as:
+```bash
+docker-compose run --rm phive install
+```
+
+**NOTE:** The volume `phive` stores the cached phar files that have been installed by PHIVE, so successive runs process faster.