gradle-plugin, readme: Add links

GRADLE_PLUGIN.md

@@ -33,7 +33,7 @@ project property (e.g. in `gradle.properties`). Note: the plugin ignores the `ko
 In this case the compiler will not be downloaded by the plugin.
 
 To use the plugin you need to define artifacts you want to build in the `konanArtifacts` block. Here you can specify
-source files and compilation parameters (e.g. a target platform) for each artifact (see **Plugin DSL** section below for
+source files and compilation parameters (e.g. a target platform) for each artifact (see [**Plugin DSL**](#plugin-dsl) section below for
 details). The plugin uses `src/main/kotlin/` as a default directory for sources.
 
     konanArtifacts {
@@ -50,8 +50,8 @@ details). The plugin uses `src/main/kotlin/` as a default directory for sources.
 ## Using C interop
 
 Kotlin/Native provides an easy interaction with native C libraries. The detailed description of this mechanism
-can be found in `INTEROP.md` while this section describes how to use Gradle to build Kotlin/Native apps using
-C libraries.
+can be found in [`INTEROP.md`](https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md) while this section
+describes how to use Gradle to build Kotlin/Native apps using C libraries.
 
 All the C libraies used should be defined in `konanInterop` block.
 
@@ -61,14 +61,16 @@ All the C libraies used should be defined in `konanInterop` block.
        }
     }
     
-Each element (interop) in this block corresponds to some native library described by a def-file (see `INTEROP.md` to
-read more about def-files). The default path to the def-file of an interop is `src/main/c_interop/<interop-name>.def`.
+Each element (interop) in this block corresponds to some native library described by a def-file (see
+[`INTEROP.md`](https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md) to read more about def-files). The
+default path to the def-file of an interop is `src/main/c_interop/<interop-name>.def`.
 
 Each interop is processed by the plugin in two steps:
 
 1. Stub generation. In this step the plugin uses `cinterop` tool to generate Kotlin and bitcode (*.bc) stubs for the
 library. You can specify additional parameters for this tool in the interop block (e.g. a custom def-file is specified
-in the example above). See **Plugin DSL** section below for available parameters and `INTEROP.md` for `cinterop` tool
+in the example above). See [**Plugin DSL**](#plugin-dsl) section below for available parameters and
+[`INTEROP.md`](https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md) for `cinterop` tool
 description.
 2. Stub compilation. In this step the plugin uses Kotlin/Native compiler to compile the stubs generated by the step (1)
 into a klib which can be linked with a Kotlin/Native application.
@@ -197,7 +199,7 @@ For this project the task graph will be the following:
                         genBarInteropStubs
     clean
 
-### Plugin DSL
+## Plugin DSL
 
      konanArtifacts {
          artifactName {