Links to local #id don't work in html preview

[kieferrm]

click don't work in the html preview even when section2 exists. This seems to be an issue with the webview.

[rebornix]

1. markdown-it doesn't support header anchor, which means, there is no id set for headers. See issues here Header anchors [needs discussion] markdown-it/markdown-it#28 and the only workaround for now is adding plugins.
2. Even if there is an anchor generated successfully, the default behavior of clicking #id (we call it bookmark) in an iframe inside a webview is opening the file again. So it will try to load file:///c%3A/Users/penlv/code/testmd/#synchronization, which is not accessible.
3. We are checking if people are clicking on bookmarks by if (node.tagName === 'A' && node.href && node.href[0] !== '#') {, however, node.href contains file name, eg, file:///c%3A/Users/penlv/code/testmd/#synchronization, node.href[0] !== '#' is always true. The correct attribute we should check is node.hash per http://www.w3schools.com/jsref/prop_anchor_hash.asp
4. scrollIntoView works here perfectly.

[kieferrm]

Resolved by commit kieferrm/vscode@521500a