Add Java 8 / gradle instructions

Adds instructions on how to use Java 8 with Gradle

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Author: alexellis

docs/cli/templates.md

@@ -129,13 +129,44 @@ npm i --save cheerio
 
 You can now add a `require('cheerio')` statement into your function and make use of this library.
 
-## 4.0 Customise a template
+## 4.0 Java
+
+A Java 8 template is provided which uses Gradle 4.8.1 as a build-system.
+
+Support is made available for external code repositories via the build.gradle file where you specify dependencies to fetch from repositories or JAR files to be added via the build.
+
+* Write a function `java-function`:
+
+```
+$ faas-cli new --lang java8 java-function
+```
+
+* Write your code in:
+
+./src/main/Handler.java
+
+* Write `junit` tests in:
+
+./src/tests/
+
+* Update gradle config if needed in:
+
+./build.gradle
+./settings.gradle
+
+* Working with headers
+
+You can use `getHeader(k)` on the Request interface to query a header.
+
+To set a header such as content-type you can use `setHeader(k, v)` on the Response interface.
+
+## 5.0 Customise a template
 
 It is recommended that you use the official templates as they are provided and if there is a short-coming that you raise a GitHub issue so we can improve the templates for everyone.
 
 All templates are driven by a Dockerfile and can be customised by editing the files found in the ./template folder.
 
-### 4.1 Update the Dockerfile
+### 5.1 Update the Dockerfile
 
 There are several reasons why you may want to update your Dockerfile, just edit `./template/<language_name>/Dockerfile`.
 
@@ -145,7 +176,7 @@ There are several reasons why you may want to update your Dockerfile, just edit
 
 * Try a new version of a base-image - it may be that the project is showing support for Node.js LTS, but you want the cutting-edge version, you can do that too
 
-### 4.2 Update a template's configuration
+### 5.2 Update a template's configuration
 
 The name of a template is read from a "template.yml" file kept within the template folder: `./template/<language_name>/template.yml`
 
@@ -159,13 +190,13 @@ fprocess: dotnet ./root.dll
 * `language` is the display name used for `faas-cli new --list`.
 * `fprocess` provides the process to run for each invocation - i.e. your function
 
-### 4.3 Use your own templates
+### 5.3 Use your own templates
 
 You can use your own Git repository for a custom or forked set of templates. This can be public or private.
 
 See `faas-cli template pull` for more information.
 
-### 5.0 ARM / Raspberry Pi
+### 6.0 ARM / Raspberry Pi
 
 Templates for ARM and Raspberry Pi are provided on a best-effort basis. If you can help with maintenance please let the project contributors know.