rename: Change the name from documentation to docs.

Author: dylan-sutton-chavez

README.md

@@ -14,7 +14,7 @@ Cargo workspace; commands work from any directory.
 ```text
 ├── compiler
 ├── demo
-├── documentation
+├── docs
 ├── runtime
 ├── starter-module
 ├── target

compiler/src/abi.rs

@@ -1,7 +1,7 @@
 /*
 Sealed module contract: op codes / tags / error kinds / HandleTable / ErrorStash / codec.
 Constants mirror `wasm-abi` byte-for-byte; extend host modules via new Op values, never new imports.
-Spec: documentation/reference/wasm-abi.md.
+Spec: docs/reference/wasm-abi.md.
 */
 
 use alloc::{string::String, vec::Vec};