[playground] No parsing of TypeScript type information?

I'm experimenting with the TSDoc Playground and I can't seem to make it parse TypeScript type information. Here's a sample:

/**
 * Returns the average of two numbers.
 *
 * @remarks
 * This method is part of the {@link core-library#Statistics | Statistics subsystem}.
 *
 * @param x - The first input number
 * @param y - The second input number
 * @returns The arithmetic mean of `x` and `y`
 *
 * @beta
 */
function getAverage(x: number, y: number) {
    return (x + y) / 2.0;
}

As you can see, the ParamBlocks in the AST don't include any type annotations for x and y.

  - ParamBlock
    - BlockTag
      * BlockTag="@param"
    * Spacing=" "
    * ParamBlock_ParameterName="x"
    * Spacing=" "
    * ParamBlock_Hyphen="-"
    * Spacing=" "
    - Section
      - Paragraph
        - PlainText
          * PlainText="The first input number"
        - SoftBreak
          * SoftBreak="\n"
  - ParamBlock
    - BlockTag
      * BlockTag="@param"
    * Spacing=" "
    * ParamBlock_ParameterName="y"
    * Spacing=" "
    * ParamBlock_Hyphen="-"
    * Spacing=" "
    - Section
      - Paragraph
        - PlainText
          * PlainText="The second input number"
        - SoftBreak
          * SoftBreak="\n"

Thoughts?

Start with the TSDoc Playground and the sample TypeScript comment in this issue, then inspect how its ParamBlock AST represents the x and y parameters. Before changing the parser, clarify whether TypeScript type annotations belong in the TSDoc AST and what their representation should be; completion requires an agreed behavior and matching Playground output.