Improve README.

Author: luhn

README.md

@@ -1,48 +1,64 @@
-CSS-URL
-=======
+gulp-rev-css-url
+================
 
-The lightweight plugin to override urls in css files to hashed after <a href="https://www.npmjs.org/package/gulp-rev">gulp-rev</a>
+A lightweight plugin for [gulp-rev](https://www.npmjs.org/package/gulp-rev) to replace CSS `url()` calls with hashed URLs.
 
-What is the result?
---
-See <a href="https://github.com/galkinrost/gulp-rev-css-url/tree/master/expected">here</a>
+This is a fork of @galkinrost's [gulp-rev-css-url](https://www.npmjs.com/package/gulp-rev-css-url), which appears to be unmaintained.
+Changes include:
 
-Install
---
-```sh
-npm install gulp-rev-css-url
-```
+- Tested against up-to-date dependencies and Node 18+.
+- Removed support for JS files.
+- Support for relative URLs.  e.g. `../images/foo.png`
+- Support for query strings and fragments.  e.g. `myfont-webfont.eot?#iefix`
 
-Usage
---
+As far as I'm aware, this is the only `gulp-rev` (or equivalent) plugin that properly handles relative URLs.
+Most will work, if at all, *only* if the relative URL backs out to the base directory.
+(Please let me know if this isn't the case!  I'd love other options.)
 
-```javascript
-var gulp=require('gulp');
-var rev=require('gulp-rev');
-var override=require('gulp-rev-css-url');
-
-gulp.task('rev',function(){
-    return gulp.src('./app/**/*')
-                .pipe(rev())
-                .pipe(override())
-                .pipe(gulp.dest('./build/'))
-                .pipe(rev.manifest())
-                .pipe(gulp.dest('./build/'));
-});
+Sample
+------
 
+Take the following simple CSS file (`css/main.css`) which references `images/dummy.jpg`.
+
+```css
+body {
+	background: url("../images/dummy.jpg");
+}
 ```
-AND
-```sh
-gulp rev
+
+After running gulp-rev with gulp-rev-css-url, the resulting CSS file might look like this:
+
+```css
+body {
+	background: url("../images/dummy-0849cad9cc.jpg
+}
 ```
 
-Tests
---
+Install
+-------
+
 ```sh
-npm test
+npm install --save-dev @luhn/gulp-rev-css-url
 ```
 
-License
-----
+Usage
+-----
+
+Add `gulp-rev-css-url` to your Gulp pipeline, directly after `gulp-rev`.
 
-MIT
+```javascript
+const gulp = require('gulp');
+const rev = require('gulp-rev');
+const override = require('gulp-rev-css-url');
+
+function rev() {
+	return gulp.src('./app/**/*')
+		.pipe(rev())
+		.pipe(override())
+		.pipe(gulp.dest('./build/'))
+		.pipe(rev.manifest())
+		.pipe(gulp.dest('./build/'));
+};
+
+exports.default = rev;
+```

package.json

@@ -1,7 +1,7 @@
 {
   "name": "gulp-rev-css-url",
   "version": "0.1.0",
-  "description": "The lightweight plugin to override urls in css files to hashed after gulp-rev",
+  "description": "A lightweight plugin for gulp-rev to replace CSS url() calls with hashed URLs.",
   "license": "MIT",
   "repository": {
     "type": "git",