feat(ci): check for dead links (cairo-book#1010)

.github/workflows/link-check.yml

@@ -0,0 +1,19 @@
+name: Check Markdown links
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  markdown-link-check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install markdown-link-check
+        run: |
+          npm install -g markdown-link-check
+      - name: Run markdown-link-check
+        run: |
+          find src -name "*.md" | xargs markdown-link-check

src/ch11-10-associated-items.md

@@ -5,10 +5,10 @@ _Associated Items_ are the items declared in [traits] or defined in
 
 [traits]: ./ch08-02-traits-in-cairo.md
 [implementations]: ./ch08-02-traits-in-cairo.md#implementing-a-trait-on-a-type
-[associated types]: ./ch11-10-associated-items-in-traits.md#associated-types
+[associated types]: ./ch11-10-associated-items.md#associated-types
 [associated functions]: ./ch05-03-method-syntax.md#associated-functions
-[associated constants]: ./ch11-10-associated-items-in-traits.md#associated-constants
-[associated implementations]: ./ch11-10-associated-items-in-traits.md#associated-implementations
+[associated constants]: ./ch11-10-associated-items.md#associated-constants
+[associated implementations]: ./ch11-10-associated-items.md#associated-implementations
 
 Associated items are useful when they are logically related to the implementation. For example, the `is_some` method on `Option` is intrinsically related to Options, so should be associated.
 

src/ch14-01-02-storage-vecs.md

@@ -6,8 +6,6 @@ The `Vec` type is provided by the Cairo core library, inside the `core::starknet
 
 > The `Array<T>` type is a **memory** type and cannot be directly stored in contract storage. For storage, use the `Vec<T>` type, which is a [phantom type][phantom types] designed specifically for contract storage. However, `Vec<T>` has limitations: it can't be instantiated as a regular variable, used as a function parameter, or included as a member in regular structs. To work with the full contents of a `Vec<T>`, you'll need to copy its elements to and from a memory `Array<T>`.
 
-[phantom types]: ./ch11-05-phantom-data.html#phantom-type-in-generics
-
 ## Declaring and Using Storage Vectors
 
 To declare a Storage Vector, use the `Vec` type enclosed in angle brackets `<>`, specifying the type of elements it will store. In Listing {{#ref storage-vecs}}, we create a simple contract that registers all the addresses that call it and stores them in a `Vec`. We can then retrieve the `n`-th registered address, or all registered addresses.