Deduplicate Re-used Headers

[avivkeller]

(Follow-up #285)

Cases like the one above should be de-duplicated into a single heading.

[moshams272]

Regarding the recent UX discussion in #655:
I know this might seem like a fairly obvious approach, but what if we visually group the overloads under a single primary heading!!

### `parseData`

This function has multiple overloaded signatures:

* **`parseData(source: string)`**
  Description for string-based parsing.

* **`parseData(source: string, options: ParseOptions)`**
  Description for parsing with custom options.

[moshams272]

Or do you feel this would still run into the same "information overload"!!

[moshams272]

After brainstormming, I think that will be better to handle Overloads by adding tag like this in md files

#### Overloads: `importModule`

##### `importModule(request, options, callback)`

* `request` {string}
* `options` {ImportModuleOptions | undefined}
* `callback` {Function}
* Returns: {void}

##### `importModule(request[, options])`

* `request` {string}
* `options` {ImportModuleOptions}
* Returns: {Promise< any >}

then make doc-kit to traverse on them and assign them like an overload boolean that helps us to not print the M for methods and do it to the name of function only to be like this:

WDUT?!