docs: add upgrade guide

Author: marionebl

docs/upgrade.md

@@ -2,4 +2,51 @@
 
 ## Version 1 to 2
 
+```sh
+npm install --save-dev conventional-changelog-lint@latest
+```
+
+### Breaking changes
+
+#### CLI
+
+* None
+
+#### Config
+
+* **wildcards** config is ignored - as of version `2.0.0` the former `.wildcards` configuration is ignored entirely. If your `.commitlintrc` or an extended shareable configuration has a `.wildcards` key a warning will be issued.
+
+#### API
+
+* None
+
 ## Version 2 to 3
+
+```sh
+npm remove --save-dev conventional-changelog-lint
+npm install --save commitlint
+mv .conventional-changelog-lintrc .commitlintrc
+```
+
+* Rename all calls to `conventional-changelog-lint` to `commitlint`
+
+### Breaking changes
+
+#### CLI
+
+* `conventional-changelog-lint` command now is called `commitlint`
+* `commitlint` command now is installed via `@commitlint/cli`
+* `.conventional-changelog-lintrc` now is called `.commitlintrc`
+* `--preset | -p` flag was removed. The `angular` preset is used always.
+
+#### Config
+
+* `.preset` key is removed. The `angular` preset is used always.
+
+#### API
+
+* `getConfiguration(name, settings, seed)` changed to `load(seed)`
+* `getMessages(range)` changed to `read(range)`
+* `getPreset(name, require)` removed
+* `format(report, options)` now only respects `.color` on `options`
+* `lint(message, options)` changed to `lint(message, rules)`