Anchor tags ID & name attributes should have same value

[gmccullo]

When using insertAnchor:true the generated anchor tags have different ID & name attribute values. The link points to the name value, not the ID value. This causes validation errors on bad links. The ID and Name should have the same value, and the link should point to it. For example:

<!-- TOC depthFrom:3 insertAnchor:true -->
- [Theatres. Clubs. Churches. Schools.](#theatres-clubs-churches-schools)
<!-- TOC -->

<a id="markdown-theatres-clubs-churches-schools" name="theatres-clubs-churches-schools"></a>
#### Theatres. Clubs. Churches. Schools.

Should be:

<!-- TOC depthFrom:3 insertAnchor:true -->
- [Theatres. Clubs. Churches. Schools.](#theatres-clubs-churches-schools)
<!-- TOC -->

<a id="theatres-clubs-churches-schools" name="theatres-clubs-churches-schools"></a>
#### Theatres. Clubs. Churches. Schools.