Fix documentation build instructions (espressif#9350)

Author: lucasssvaz

docs/en/guides/docs_contributing.rst

@@ -72,11 +72,11 @@ We also recommend you install to grammar check extension to help you to review E
 Building
 ********
 
-To build the documentation and generate the HTLM files, you can use the following command inside the ``docs`` folder. After a successful build, you can check the files inside the `build/html` folder.
+To build the documentation and generate the HTML files, you can use the following command inside the ``docs`` folder. After a successful build, you can check the files inside the `_build/en/generic/html` folder.
 
 .. code-block::
 
- make html
+ build-docs -l en
 
 This step is essential to ensure that there are no syntax errors and also to see the final result.
 
@@ -104,7 +104,7 @@ If everything is ok, you will see some output logs similar to this one:
  dumping object inventory... done
  build succeeded.
 
-The HTML pages are in build/html.
+The HTML pages are in `_build/en/generic/html`.
 
 Sections
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