Proposal: Hero Header should allow for optional h1 text

[ahmadnassri]

this is useful when data.heroImage can act as the "header" (e.g. logo & label of product / application are present in image)

• allow removing the h1 tag when data.heroText is NULL
• allow passing data.heroAlt to define alt text value.

Summary

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Docs
• Build-related changes
• Other, please describe:

If changing the UI of default theme, please provide the before/after screenshot:

Before

After

with data.heroText === null

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

You have tested in the following browsers: (Providing a detailed version will be better.)

• Chrome
• Firefox
• Safari
• Edge
• [ x IE

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature
• Related documents have been updated
  • I have not updated docs yet, but I will if this is given 👍
• Related tests have been updated
  • this will need new tests, happy to provide them if this is given 👍

To avoid wasting your time, it's best to open a feature request issue first and wait for approval before working on it.

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