Add IDs for Stages and self-links

Stages.md

@@ -46,8 +46,8 @@ These checkpoints are modeled loosely on the [TC39 process](https://tc39.es/proc
    <th>Specification quality at entrance
  </thead>
  <tbody>
-  <tr>
-   <td>Stage 0<br>(Proposal)
+  <tr id="stage0">
+   <td>Stage 0<a class="self-link" href="#stage0"></a><br>(Proposal)
    <td>—
    <td>
     <ul>
@@ -57,8 +57,8 @@ These checkpoints are modeled loosely on the [TC39 process](https://tc39.es/proc
     <ul>
      <li>An explainer describing the problem to be solved, including sketching use cases and scenarios. This explainer can exist anywhere, including in a GitHub issue or a personal repository.
     </ul>
-  <tr>
-   <td>Stage 1<br>(Incubation)
+  <tr id="stage1">
+   <td>Stage 1<a class="self-link" href="#stage1"></a><br>(Incubation)
    <td>
     <ul>
      <li>A comprehensive explainer for the <a href="./IPR%20Policy.md#21-contribution">Contribution</a>, in a standards organization-approved incubation venue such as a <a href="https://www.w3.org/community/groups/">W3C CG</a> or a branch of an existing WHATWG Standard.
@@ -77,8 +77,8 @@ These checkpoints are modeled loosely on the [TC39 process](https://tc39.es/proc
     <ul>
      <li>The explainer follows the guidelines at <a href="https://tag.w3.org/explainers/">https://tag.w3.org/explainers/</a>.
     </ul>
-  <tr>
-   <td>Stage 2<br>(Iteration)
+  <tr id="stage2">
+   <td>Stage 2<a class="self-link" href="#stage2"></a><br>(Iteration)
    <td>
     <ul>
      <li>A draft specification for the <a href="./IPR%20Policy.md#21-contribution">Contribution</a>, in a standards organization-approved incubation venue (see stage 1).
@@ -93,8 +93,8 @@ These checkpoints are modeled loosely on the [TC39 process](https://tc39.es/proc
     <ul>
      <li>The draft specification uses Web IDL to define any new JavaScript APIs, roughly matches the style of the standard it's expected to merge into, and has a processing model, including full algorithms. However, there may be rough edges or TODOs in the processing model.
     </ul>
-  <tr>
-   <td>Stage 3<br>(Committed)
+  <tr id="stage3">
+   <td>Stage 3<a class="self-link" href="#stage3"></a><br>(Committed)
    <td>
     <ul>
      <li>Complete specification text.
@@ -112,8 +112,8 @@ These checkpoints are modeled loosely on the [TC39 process](https://tc39.es/proc
      <li>Specification is complete: all data structures, processing model, and API are fully described. (It may still have small issues that will be identified by editor review during this stage.)
      <li>Full specification and comprehensive tests are completed; pull request template is filled out with all checkboxes checked.
     </ul>
-  <tr>
-   <td>Stage 4 (Standard)  
+  <tr id="stage4">
+   <td>Stage 4<a class="self-link" href="#stage4"></a><br>(Standard)  
    <td>
     <ul>
      <li>Editor’s comments on the pull request have all been resolved, and the pull request for the <a href="./IPR%20Policy.md#21-contribution">Contribution</a> has been merged by the Editor.