minor #17 Adding CHANGELOG (weaverryan)

This PR was merged into the main branch.

Discussion
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Adding CHANGELOG

Hi!

I'd personally like a CHANGELOG - I rely on them a lot in the JS world, as things change a lot. And also, with the breaking change in 1.2.0, I think it would help.

Cheers!

Commits
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983d794 Adding CHANGELOG

Author: tgalopin

CHANGELOG.md

@@ -0,0 +1,20 @@
+# CHANGELOG
+
+## 1.2.0
+
+* Webpack integration with this library has changed. If you're using
+  Webpack Encore, you must upgrade to version 1.0.0 or higher of that
+  library - #14.
+
+* Controller names were changed and normalized - #12
+
+  Before: `@symfony/ux-dropzone/dropzone`
+  After: `symfony--ux-dropzone--dropzone`
+
+## 1.1.0
+
+* Support for Stimulus 1 dropped and support for Stimulus 2 added - #4.
+
+## 1.0.0
+
+* Initial release!

README.md

@@ -39,6 +39,8 @@ import { startStimulusApp } from '@symfony/stimulus-bridge';
 export const app = startStimulusApp(require.context('./controllers', true, /\.(j|t)sx?$/));
 ```
 
+## Common Errors
+
 If you get this error:
 
 > ./assets/bootstrap.js contains a reference to the file @symfony/autoimport.
@@ -53,6 +55,12 @@ Remove the following line in the mentioned file: it's not needed anymore:
 - import '@symfony/autoimport';
 ```
 
+If you get the error:
+
+> Cannot find module '@symfony/stimulus-bridge/webpack-helper'
+
+Be sure to upgrade to `@symfony/webpack-encore` version 1.0.0 or higher.
+
 ## Run tests
 
 ```sh