Fix Markdown links

Author: abrown

design/mvp/Async.md

@@ -749,7 +749,7 @@ comes after:
 [`yield`]: Explainer.md#-yield
 [`waitable-set.wait`]: Explainer.md#-waitable-setwait
 [`waitable-set.poll`]: Explainer.md#-waitable-setpoll
-[`thread.spawn*`]: Explainer.md#-threadspawnref
+[`thread.spawn*`]: Explainer.md#-threadspawn_ref
 [ESM-integration]: Explainer.md#ESM-integration
 
 [Canonical ABI Explainer]: CanonicalABI.md

design/mvp/CanonicalABI.md

@@ -54,7 +54,8 @@ being specified here.
   * [`canon error-context.new`](#-canon-error-contextnew) 🔀
   * [`canon error-context.debug-message`](#-canon-error-contextdebug-message) 🔀
   * [`canon error-context.drop`](#-canon-error-contextdrop) 🔀
-  * [`canon thread.spawn`](#-canon-threadspawn) 🧵
+  * [`canon thread.spawn_ref`](#-canon-threadspawn_ref) 🧵
+  * [`canon thread.spawn_indirect`](#-canon-threadspawn_indirect) 🧵
   * [`canon thread.available_parallelism`](#-canon-threadavailable_parallelism) 🧵
 
 ## Supporting definitions

design/mvp/Explainer.md

@@ -2823,8 +2823,8 @@ For some use-case-focused, worked examples, see:
 [`canon_error_context_new`]: CanonicalABI.md#-canon-error-contextnew
 [`canon_error_context_debug_message`]: CanonicalABI.md#-canon-error-contextdebug-message
 [`canon_error_context_drop`]: CanonicalABI.md#-canon-error-contextdrop
-[`canon_thread_spawn_ref`]: CanonicalABI.md#-canon-threadspawnref
-[`canon_thread_spawn_indirect`]: CanonicalABI.md#-canon-threadspawnindirect
+[`canon_thread_spawn_ref`]: CanonicalABI.md#-canon-threadspawn_ref
+[`canon_thread_spawn_indirect`]: CanonicalABI.md#-canon-threadspawn_indirect
 [`canon_thread_available_parallelism`]: CanonicalABI.md#-canon-threadavailable_parallelism
 [`pack_async_copy_result`]: CanonicalABI.md#-canon-streamfuturereadwrite
 [the `close` built-ins]: CanonicalABI.md#-canon-streamfutureclose-readablewritable