Adding devfile and 'Developer Workspace' button in readme for trying the project on Hosted Che / che.openshift.io

Signed-off-by: Ilya Buziuk <ibuziuk@redhat.com>

Author: ibuziuk

devfile.yaml

@@ -0,0 +1,40 @@
+---
+apiVersion: 1.0.0
+metadata:
+  name: jbang
+components:
+  -
+    type: chePlugin
+    id: redhat/java/latest
+  -
+    type: dockerimage
+    alias: gradle
+    image: quay.io/eclipse/che-java11-gradle:nightly
+    env:
+      - name: GRADLE_USER_HOME
+        value: /home/gradle/.gradle
+      - name: JAVA_OPTS
+        value: "-XX:MaxRAMPercentage=50 -XX:+UseParallelGC -XX:MinHeapFreeRatio=10
+          -XX:MaxHeapFreeRatio=20 -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90
+          -Dsun.zip.disableMemoryMapping=true -Xms20m -Djava.security.egd=file:/dev/./urandom"
+      - name: JAVA_TOOL_OPTIONS
+        value: "-XX:MaxRAMPercentage=50 -XX:+UseParallelGC -XX:MinHeapFreeRatio=10
+          -XX:MaxHeapFreeRatio=20 -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90
+          -Dsun.zip.disableMemoryMapping=true -Xms20m -Djava.security.egd=file:/dev/./urandom"
+      - name: HOME
+        value: /home/gradle
+    memoryLimit: 512Mi
+    volumes:
+      - name: gradle
+        containerPath: /home/gradle/.gradle
+    mountSources: true
+commands:
+  -
+    name: build
+    actions:
+      -
+        type: exec
+        component: gradle
+        command: "./gradlew"
+        workdir: ${CHE_PROJECTS_ROOT}/jbang
+

readme.adoc

@@ -37,6 +37,10 @@ hello made with jbang
 
 Instant cli app generated built using java and picocli as a dependency that was fetched as needed for the compilation and execution.
 
+== Try it online on Hosted Che at https://che.openshift.io[che.openshift.io]
+
+image:https://che.openshift.io/factory/resources/factory-contribute.svg[Contribute, link=https://che.openshift.io/f?url=https://github.com/maxandersen/jbang]
+
 == Features
 
 * `.java` Scripting for Java 8 and upwards