[skip ci] docs: Now -js and -debug are removed

`-js` is generalized as RubyGems integration, and `-debug` is now by
default.

Author: kateinoigakukun

CONTRIBUTING.md

@@ -21,7 +21,7 @@ $ rake --tasks
 $ rake build:download_prebuilt
 
 # Build Ruby (if you need to build Ruby by yourself)
-$ rake build:head-wasm32-unknown-wasi-full-js-debug
+$ rake build:head-wasm32-unknown-wasi-full
 
 # Build npm package
 $ rake npm:ruby-head-wasm-wasi
@@ -55,8 +55,8 @@ $ rake build:head-wasm32-unknown-wasi-full:clean
 $ rake build:head-wasm32-unknown-wasi-full:remake
 
 # Output is in the `rubies` directory
-$ tree -L 3 rubies/head-wasm32-unknown-wasi-full-js
-rubies/head-wasm32-unknown-wasi-full-js/
+$ tree -L 3 rubies/head-wasm32-unknown-wasi-full
+rubies/head-wasm32-unknown-wasi-full/
 ├── usr
 │   └── local
 │       ├── bin
@@ -72,9 +72,9 @@ Please follow the official instructions to install.
 
 ```console
 # Build only a specific combination of ruby version, profile, and target
-$ rake build:head-wasm32-unknown-emscripten-full-js
+$ rake build:head-wasm32-unknown-emscripten-full
 # Output is in the `rubies` directory
-$ tree -L 3 rubies/head-wasm32-unknown-emscripten-full-js
+$ tree -L 3 rubies/head-wasm32-unknown-emscripten-full
 rubies/head-wasm32-unknown-emscripten-full
 └── usr
     └── local

README.md

@@ -137,14 +137,6 @@ A _build_ is a combination of ruby version, _profile_, and _target_.
       <td><code>full</code></td>
       <td>All standard extension libraries</td>
     </tr>
-    <tr>
-      <td><code>*-js</code></td>
-      <td>Enabled JS interoperability, only usable with npm package</td>
-    </tr>
-    <tr>
-      <td><code>*-debug</code></td>
-      <td>With DWARF info and <a href="https://webassembly.github.io/spec/core/appendix/custom.html#name-section" rel="nofollow"><code>name</code> section</a> for debugging</td>
-    </tr>
   </tbody>
 </table>