sdk: add page (#2389)

pages/common/sdk.md

@@ -0,0 +1,28 @@
+# sdk
+
+> Tool for managing parallel versions of multiple Software Development Kits.
+> Supports Java, Groovy, Scala, Kotlin, Gradle, Maven, Vert.x and many others.
+
+- Install a specific version of Gradle:
+
+`sdk install {{gradle}} {{gradle_version}}`
+
+- Switch to a specific version of Gradle:
+
+`sdk use {{gradle}} {{gradle_version}}`
+
+- Check current Gradle version:
+
+`sdk current {{gradle}}`
+
+- List all Software Development Kits available to install:
+
+`sdk list`
+
+- Update Gradle to the latest version:
+
+`sdk upgrade {{gradle}}`
+
+- Uninstall a particular version of Gradle:
+
+`sdk rm {{gradle}} {{gradle_version}}`