Add README with a basic usage section

Author: BrenekH

README.md

@@ -0,0 +1,50 @@
+# Markdown Table Generator
+
+Generate markdown tables from a JSON definition for publication on [locatarr.github.io](https://locatar.github.io).
+
+## Usage
+
+### JSON file format
+
+```jsonc
+{
+ "applications": [
+ {
+ "name": "AppName",
+ "description": "App Description",
+ "github_slug": "github/link", // github_slug is an optional field
+ "subreddit": "r/subreddit" // subreddit is an optional field
+ }
+ ]
+}
+```
+
+### Generate from a file
+
+```bash
+$ markdown-table-generator myfile.json
+| **Application** | **Description** | **Github** | **Reddit** |
+|-|-|-|-|
+| AppName | App Description | GitHub Link | Subreddit |
+...
+```
+
+### Generate from standard input
+
+```bash
+$ cat myfile.json | markdown-table-generator -
+| **Application** | **Description** | **Github** | **Reddit** |
+|-|-|-|-|
+| AppName | App Description | GitHub Link | Subreddit |
+...
+```
+
+OR
+
+```bash
+$ cat myfile.json | markdown-table-generator
+| **Application** | **Description** | **Github** | **Reddit** |
+|-|-|-|-|
+| AppName | App Description | GitHub Link | Subreddit |
+...
+```