Update copy command in MkDocs build instruction to prevent copying to wrong location

build.md

@@ -128,10 +128,14 @@ and will be used for MkDocs configuration later.
 Copy the processed Markdown files and ontology files to the `docs/` directory:
 
 ```shell
-cp -R parser_output/mkdocs spdx-spec/docs/model 
-cp -R parser_output/rdf spdx-spec/docs/rdf
+mkdir -p spdx-spec/docs/model
+mkdir -p spdx-spec/docs/rdf
+cp -R parser_output/mkdocs/* spdx-spec/docs/model 
+cp -R parser_output/rdf/* spdx-spec/docs/rdf
 ```
 
+### 3.3 Generate a complete MkDocs configuration file
+
 To ensure MkDocs recognizes the new Markdown files,
 insert the model file list from `parser_output/model-files.yml`
 into the MkDocs configuration file in `spdx-spec/mkdocs.yml`.
@@ -152,7 +156,7 @@ we will use MkDocs to assemble them into a website.
 
 *Note: all the commands below use the configuration file*
 *with the model file list, `mkdocs-full.yml`,*
-*generated in the [step 3.2](#32-copying-the-generated-files).*
+*generated in [step 3.3](#33-generate-a-complete-mkdocs-configuration-file).*
 *If you only want to review the non-model part of the specification*
 *(have skipped step 3), please use `mkdocs.yml` instead.*
 
@@ -179,10 +183,7 @@ These following commands should run inside the `spdx-spec/` directory.
 ## 5. Configuring the website
 
 To make additional adjustments to the website,
-you can modify its configuration.
-
-Inside `spdx-spec/` directory, there is a file `mkdocs.yml`.
-This is a configuration file for MkDocs.
+you can modify the configuration file at `spdx-spec/mkdocs.yml`.
 
 For example, you can customize website details like the site name
 and main URL (canonical URL) in this file.
@@ -191,6 +192,10 @@ To include a page in the navigation bar, list its filename under the `nav:`
 section. The order of filenames in this section determines the order of the
 page in the navigation bar.
 
+After you have modified the configuration file, you may need to rerun
+[step 3.3](#33-generate-a-complete-mkdocs-configuration-file)
+to incorporate the changes into the complete configuration file.
+
 ## 6. Specification versions on spdx.github.io
 
 The SPDX specifications on <https://spdx.github.io/spdx-spec/> are built