docs(readme): add table of contents and document content collections

README.md

@@ -1,3 +1,19 @@
+<!--toc:start-->
+- [What this is](#what-this-is)
+  - [Experience as a taxonomy](#experience-as-a-taxonomy)
+- [Tech](#tech)
+- [Commands](#commands)
+- [Content](#content)
+  - [Projects (`src/content/projects`)](#projects-srccontentprojects)
+  - [Experience (`src/content/experience`)](#experience-srccontentexperience)
+  - [Writing (`src/content/writing`)](#writing-srccontentwriting)
+  - [Speaking (`src/content/speaking`)](#speaking-srccontentspeaking)
+- [Configure](#configure)
+- [Deploy](#deploy)
+- [Acknowledgment](#acknowledgment)
+- [License](#license)
+<!--toc:end-->
+
 <div align="center">
   <img alt="Prad Nukala" src="./public/avatar.png" width="96" />
 </div>
@@ -49,11 +65,12 @@ Content lives in `src/content/<collection>` as `.md`/`.mdx` files; the filename
 | Property        | Required | Notes                                              |
 | --------------- | :------: | -------------------------------------------------- |
 | `title`         |    ✓     | Max 60 chars.                                      |
-| `publishDate`   |    ✓     | ISO 8601 (offsets allowed).                        |
+| `startDate`     |    ✓     | Date.                                              |
+| `endDate`       |          | Omit for ongoing projects. Projects are sorted by `endDate`, most recent first (ongoing on top). |
 | `description`   |          | Used for meta description.                         |
 | `link`          |          | URL to the live project.                           |
 | `repo`          |          | URL to the source repository.                      |
-| `tags`          |          | String array.                                      |
+| `tags`          |          | Skills/technologies — double as tags for cross-project browsing at `/projects/tags/<tag>`. |
 | `experiences`   |          | Array of experience ids this project is filed under. |
 
 ### Experience (`src/content/experience`)