Add Golang to the quickstart guide (redhat-developer#5788)

* Adds Java Spring Boot example to quickstart guide

<!--
Thank you for opening a PR! Here are some things you need to know before submitting:

1. Please read our developer guideline: https://github.com/redhat-developer/odo/wiki/Dev:-odo-Dev-Guidelines
2. Label this PR accordingly with the '/kind' line
3. Ensure you have written and ran the appropriate tests: https://github.com/redhat-developer/odo/wiki/Dev:-Writing-and-running-tests
4. Read how we approve and LGTM each PR: https://github.com/redhat-developer/odo/wiki/Pull-Requests:-Review-guideline

Documentation:

If you are pushing a change to documentation, please read: https://github.com/redhat-developer/odo/wiki/Documentation:-Contributing
-->

**What type of PR is this:**

<!--
Add one of the following kinds:
/kind bug
/kind feature
/kind cleanup
/kind tests

Feel free to use other [labels](https://github.com/redhat-developer/odo/labels) as needed. However one of the above labels must be present or the PR will not be reviewed. This instruction is for reviewers as well.
-->
/kind documentation

**What does this PR do / why we need it:**

Adds a Java Spring Boot example to the quickstart

**Which issue(s) this PR fixes:**
<!--
Specifying the issue will automatically close it when this PR is merged
-->

Closes redhat-developer#5746

**PR acceptance criteria:**

- [X] Documentation

**How to test changes / Special notes to the reviewer:**

Signed-off-by: Charlie Drage <[email protected]>

* Add Golang to the quickstart guide

<!--
Thank you for opening a PR! Here are some things you need to know before submitting:

1. Please read our developer guideline: https://github.com/redhat-developer/odo/wiki/Dev:-odo-Dev-Guidelines
2. Label this PR accordingly with the '/kind' line
3. Ensure you have written and ran the appropriate tests: https://github.com/redhat-developer/odo/wiki/Dev:-Writing-and-running-tests
4. Read how we approve and LGTM each PR: https://github.com/redhat-developer/odo/wiki/Pull-Requests:-Review-guideline

Documentation:

If you are pushing a change to documentation, please read: https://github.com/redhat-developer/odo/wiki/Documentation:-Contributing
-->

**What type of PR is this:**

<!--
Add one of the following kinds:
/kind bug
/kind feature
/kind cleanup
/kind tests

Feel free to use other [labels](https://github.com/redhat-developer/odo/labels) as needed. However one of the above labels must be present or the PR will not be reviewed. This instruction is for reviewers as well.
-->
/kind documentation

**What does this PR do / why we need it:**

Testing out Golang with `odo` was really straight forward and simple,
and I thought I may as well add it to the quick start guide!

**Which issue(s) this PR fixes:**
<!--
Specifying the issue will automatically close it when this PR is merged
-->

N/A

**PR acceptance criteria:**

- [X] Documentation

**How to test changes / Special notes to the reviewer:**

Signed-off-by: Charlie Drage <[email protected]>

* update

* add odo delete