Add documentation and implementation example for the abi keyword in keyword_docs.rs.

Author: JoshuaBatty

sway-lsp/src/utils/keyword_docs.rs

@@ -680,6 +680,36 @@ impl KeywordDocs {
             mod continue_keyword {}
         };
 
+        let abi_keyword: ItemMod = parse_quote! {
+            /// Defines an Application Binary Interface (ABI).
+            ///
+            /// An `abi` block defines a set of methods that a contract exposes externally. It acts as the
+            /// public interface for interacting with a smart contract. Only one `abi` block is allowed per
+            /// contract.
+            ///
+            /// The methods defined within an `abi` block must be implemented in an associated [`impl`] block
+            /// for the contract.
+            ///
+            /// ```sway
+            /// contract;
+            ///
+            /// abi MyContract {
+            ///     #[storage(read, write)]
+            ///     fn update_counter(amount: u64) -> u64;
+            /// }
+            ///
+            /// impl MyContract for Contract {
+            ///     #[storage(read, write)]
+            ///     fn update_counter(amount: u64) -> u64 {
+            ///         let current = storage.counter;
+            ///         storage.counter = current + amount;
+            ///         storage.counter
+            ///     }
+            /// }
+            /// ```
+            mod abi_keyword {}
+        };
+
         // TODO
         let str_keyword: ItemMod = parse_quote! {
             mod str_keyword {}
@@ -725,11 +755,6 @@ impl KeywordDocs {
             mod mod_keyword {}
         };
 
-        // TODO
-        let abi_keyword: ItemMod = parse_quote! {
-            mod abi_keyword {}
-        };
-
         // TODO
         let storage_keyword: ItemMod = parse_quote! {
             mod storage_keyword {}