Use Deploying an Application not Deploying application (redhat-develo…

…per#6144)

<!--
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:**

Updates correct grammar for title to Deploying an Application

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

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

docs/website/docs/user-guides/advanced/deploy/deploy.md

@@ -1,5 +1,5 @@
 ---
-title: Deploying application
+title: Deploying an Application
 ---
 
 In this guide, we will be using odo to create deploy to production a "Hello World" application.