v0.13.0

Every component instance now knows where it was written. On the dev server,
custom elements in html templates and in index.html carry their line and
column, so the Components, Timeline and Updates views and the source overlay
can open the template tag that rendered a given instance, not only the class
behind it. The overlay tooltip becomes a readout that lights up the row a
click will open. Nothing needs action to upgrade, but tests that match
attributes exactly will see the new dev-only data-lit-source.

Added

• Jump to where a component instance is rendered. The Components panel
  shows a "Rendered at" link next to the declaration that opens the html
  template, or index.html, at the line and column of the tag that created
  this instance. To make that possible the dev server stamps a
  data-lit-source attribute on those elements while sourceOverlay is on;
  production builds never get it.
• The source overlay opens the call site too. Its tooltip shows a
  "rendered at" row under the declaration, and Ctrl/⌘+Shift+click opens it.
  Library elements picked with hosts: 'lit' have no declaration, so
  Ctrl/⌘+click opens their call site instead. onSelect receives the new
  callSite, and a custom EditorConfig.url gets an optional column.
• The overlay shows which file a click will open. Holding Ctrl/⌘ lights
  up the declaration row, now marked with the Components tab's cube, and
  adding Shift lights up the "rendered at" row.
• Timeline and Updates link to where an element is rendered. A selected
  span, and the updates of a single instance, show a "Rendered at" link next
  to the source link.
• The Settings tab says why a feature is on or off. The HMR, Source
  Overlay and Timeline headers now tag their enabled or disabled pill with
  (option) or (env) when your config set it, like the rows below them.

Changed

• The overlay tooltip is a readout, not a control. The pointer never
  settled on it long enough to click, so its open icons are no longer buttons
  and the pointer passes through to the page underneath, which can now be
  picked there too.

Fixed

• A snapshot from lit-devtools dev no longer promises HMR or source
  links. The frozen panel now offers what the host that recorded the
  session could do, instead of assuming the Vite plugin.

Removed

• The overlay tooltip's copy button. It sat out of the pointer's reach;
  the path is still shown in the tooltip and in the Components panel.