Made PageProps componentMapping property optional as it is already trated as optional inside the component

[RomanKontsevoi]

Description

Just made componentMapping prop optioanl because it is already treated as optional

Related Issue

#225

Motivation and Context

Less TS errors using the library

How Has This Been Tested?

I hadn't made tests, because it is a really straightforward and tiny only TS-related fix. The error itself says that the issue is that 'componentMapping' property is required, however the code itself assumes it can be not defined:

const PageList = ({ cqChildren, ...props }: PageProps): JSX.Element => {
  const componentMapping = props.componentMapping || ComponentMapping;
...

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.