Add component-name-in-template-casing to strongly-recommended

[stevenadams]

Add the component-name-in-template-casing rule to strongly-recommended category as per the style guide

[michalsnik]

Hey @stevenadams, thanks for the PR. Putting rules in undefined category is part of the flow. This rule was kind of controversial and had lots of comments in the first place so we decided to give it some time, and put it in strongly recommended afterwards. I'm going to close this PR for now, as we're going to evaluate currently uncategorized rules soon anyway :) I'm glad you're on top of the style guide and what's happening in Vue. I appreciate your concern!