chore: update README

README.md

@@ -1,2 +1,76 @@
 # mill-missinglink
-A Mill plugin for missinglink
+
+A Mill plugin for [missinglink](https://github.com/spotify/missinglink), ported from [sbt-missinglink](https://github.com/scalacenter/sbt-missinglink)
+
+## Usage
+
+Add the following lines in `build.sc`:
+
+```scala
+import $ivy.`io.github.hoangmaihuy::mill-missinglink::<latest-version>`
+```
+
+Extends `MissinglinkCheckModule`
+
+```scala
+import io.github.hoangmaihuy.missinglink._
+
+object example extends MissinglinkCheckModule
+```
+
+Then, run `missinglinkCheck` command
+
+```bash 
+> mill example.missinglinkCheck
+```
+
+Currently, `missinglinkCheck` only checks conflicts in **Runtime** scope.
+
+### Do not fail on conflicts
+
+By default, the plugin fails the build if any conflicts are found.
+It can be disabled by the `missinglinkFailOnConflicts` setting:
+
+```scala
+object example extends MissinglinkCheckModule {
+  overide def missinglinkFailOnConflicts = false
+}
+```
+
+### Ignore conflicts in certain packages
+
+Conflicts can be ignored based on the package name of the class that has the conflict.
+There are separate configuration options for ignoring conflicts on the "source" side of the conflict and the "destination" side of the conflict.
+Packages on the source side can be ignored with `missinglinkIgnoreSourcePackages` and packages on the destination side can be ignored with `missinglinkIgnoreDestinationPackages`:
+
+```scala
+object example extends MissinglinkCheckModule {
+  override def missinglinkIgnoreDestinationPackages = Seq(IgnoredPackage("com.google.common"))
+  override def missinglinkIgnoreSourcePackages = Seq(IgnoredPackage("com.example"))
+}
+```
+
+By default, all subpackages of the specified package are also ignored, but this can be disabled by the `ignoreSubpackages` field: `IgnoredPackage("test", ignoreSubpackages = false)`.
+
+### Excluding some dependencies from the analysis
+
+You can exclude certain dependencies using `DependencyFilter`:
+
+```scala
+object example extends MissinglinkCheckModule {
+  missinglinkExcludedDependencies = Seq(DependencyFilter(organization = "com.google.guava"))
+  missinglinkExcludedDependencies = Seq(DependencyFilter(organization = "ch.qos.logback", name = "logback-core"))
+}
+```
+
+## More information
+
+This plugin was ported from ported from [sbt-missinglink](https://github.com/scalacenter/sbt-missinglink). Core functions were copied from `sbt-missinglink` with some modifications to work with Mill.
+
+You can find more information about the problem statement, caveats and
+limitations, etc. in the upstream project
+[missinglink](https://github.com/spotify/missinglink).
+
+## Licenses
+
+This software is released under the Apache License 2.0. More information in the file LICENSE distributed with this project.