Added Dockerfile for running these commands through a container (#4)

* Add Dockerfile

* Add instructions for Docker usage

Dockerfile

@@ -0,0 +1,10 @@
+FROM alpine:latest
+
+RUN apk add --no-cache git gcc musl-dev && \
+    git clone https://github.com/bucanero/ps3iso-utils.git && \
+    find ps3iso-utils -type f -name "*.c" -exec \
+    sh -c 'OFILE=`basename "{}" ".c"` && gcc "{}" -o /usr/local/bin/"$OFILE"' \; && \
+    rm -rf ps3iso-utils && \
+    apk del git gcc musl-dev
+
+WORKDIR /tmp

README.md

@@ -4,7 +4,7 @@
 [![Build Windows binaries](https://github.com/bucanero/ps3iso-utils/actions/workflows/build-win.yml/badge.svg)](https://github.com/bucanero/ps3iso-utils/actions/workflows/build-win.yml)
 [![License](https://img.shields.io/github/license/bucanero/ps3iso-utils.svg)](./LICENSE)
 
-Windows, Linux, and macOS builds of [Estwald's](https://github.com/Estwald) PS3 ISO utilities:
+Windows, Linux, macOS, and [Docker](#docker) builds of [Estwald's](https://github.com/Estwald) PS3 ISO utilities:
 
 - [extractps3iso](#extractps3iso)
 - [makeps3iso](#makeps3iso)
@@ -57,3 +57,71 @@ Usage:
 | :----- | :------ |
 `splitps3iso`                       | interactive console input
 `splitps3iso <ISO file>`            | split ISO image (4Gb)
+
+# Docker
+
+It is possible to run these commands through a Docker or Podman container. The image size is less than 7MB.
+
+1. Download the `Dockerfile`
+
+2. Build the Docker image:
+
+```
+$ docker build -t ps3iso-utils .
+```
+
+3. Append the following functions to your `.bashrc`:
+
+```
+extractps3iso () {
+	docker run --rm -v "$PWD":/tmp localhost/ps3iso-utils extractps3iso "$@"
+}
+
+makeps3iso () {
+	docker run --rm -v "$PWD":/tmp localhost/ps3iso-utils makeps3iso "$@"
+}
+
+patchps3iso () {
+	docker run --rm -v "$PWD":/tmp localhost/ps3iso-utils patchps3iso "$@"
+}
+
+splitps3iso () {
+	docker run --rm -v "$PWD":/tmp localhost/ps3iso-utils splitps3iso "$@"
+}
+
+```
+
+4. Source your `.bashrc` or close and reopen your terminal:
+
+```
+$ source ~/.bashrc
+```
+
+5. Run the program
+
+Examples:
+
+```
+$ splitps3iso --help
+
+SPLITPS3ISO (c) 2021, Bucanero
+
+Usage:
+
+    splitps3iso                       -> input data from the program
+    splitps3iso <ISO file>            -> split ISO image (4Gb)
+```
+
+```
+$ makeps3iso BLUS12345
+
+MAKEPS3ISO (c) 2013, Estwald (Hermes)
+
+
+</>     
+  -> PS3_DISC.SFB LBA 58 size 1 KB
+</PS3_GAME>                  
+  -> ICON0.PNG LBA 59 size 46 KB
+...
+```
+