Add docs

Author: rainboyan

build.gradle

@@ -26,6 +26,7 @@ apply plugin: "org.graceframework.grace-web"
 apply plugin: "org.graceframework.asset-pipeline"
 apply plugin: "com.github.erdi.webdriver-binaries"
 apply plugin: "org.graceframework.grace-gsp"
+apply from: 'gradle/docs.gradle'
 
 repositories {
     // mavenLocal()

docs/guide/introduction.adoc

@@ -0,0 +1,5 @@
+Grace Dynamic Modules Plugin (GDMP) offer new ways of creating modular and maintainable Grace applications.
+
+It's a Grace plugin can implement one or more plugin modules to develop and extend Grace applications.
+
+We can use Dynamic Modules to maximize the use of Grace plugins and create an open, shared, and reusable plugin market.

docs/guide/toc.yml

@@ -0,0 +1,2 @@
+introduction: Introduction
+usage: Usage

docs/guide/usage.adoc

@@ -0,0 +1,21 @@
+Add `dynamic-modules` plugin to your `build.gradle`,
+
+[source,groovy]
+----
+apply plugin: "org.graceframework.grace-gsp"
+
+repositories {
+    mavenCentral()
+    maven {
+        url "https://s01.oss.sonatype.org/content/repositories/snapshots/"
+        mavenContent {
+            snapshotsOnly()
+        }
+    }
+}
+
+dependencies {
+    implementation "org.graceframework:grace-plugin-api"
+    implementation "org.graceframework.plugins:dynamic-modules:VERSION"
+}
+----