Add how-to-use section to readme file (#9)

Author: ApexModder

README.md

@@ -1,3 +1,50 @@
 # ☃️ Snowblower
 
 A utility to create a git repository of Minecraft decompiled code to make it easier to see what changed between minecraft versions.
+
+## How to use
+
+This section covers the basic command-line usage for generating a repository of decompiled Minecraft code. Most users can simply run the tool locally as described below.
+
+You can download the latest and previous versions of Snowblower directly from its [project page](https://projects.neoforged.net/neoforged/snowblower).
+
+### Basic usage
+
+The most common use case is to generate a comprehensive repository of all supported versions. The following command processes every version starting from `1.14.4`, which is the first version where official Mojang mappings are available.
+
+```sh
+java -jar Snowblower.jar --output $OUTPUT --branch $BRANCH --start-over-if-required
+```
+
+- `--output $OUTPUT`: Specifies the output directory for the generated repository.
+  - This can be specified either as an absolute path or some path releative to the `jar` file.
+  - `output/$BRANCH` or `output/$VERSION` is recommended to keep your generated repositories organized. (`$VERSION` being a specific Minecraft version)
+- `--branch $BRANCH`: Designates the target branch, which can be `release` or `dev`.
+  - Using `dev` will include snapshots in the generated output.
+- `--start-over-if-required`: Ensures the process starts from scratch if necessary.
+
+**Note**: Generating every version takes a considerable amount of time.
+
+### Excluding unnecessary files
+
+To prevent repository clutter and large diffs, especially with structures (`.nbt`) and images (`.png`), it is recommended to exclude them. These files frequently change due to internal version values, causing noise in the commit history.
+
+```sh
+java -jar Snowblower.jar --output $OUTPUT --branch $BRANCH --exclude "**.nbt" --exclude "**.png" --start-over-if-required
+```
+
+### Processing specific versions
+
+If you need to generate a repository for a limited range of versions, you can use the `--start-ver` and `--target-ver` flags. This will process everything from the specified start version up to and including the target version.
+
+```sh
+java -jar Snowblower.jar --output $OUTPUT --branch $BRANCH --start-ver 1.20.1 --target-ver 1.21 --start-over-if-required
+```
+
+### Exploring more flags
+
+Snowblower has many more flags and options for advanced users. You can see a complete list by running the jar file without any arguments.
+
+```sh
+java -jar Snowblower.jar
+```