Fixed a typo

Cloning was spelled wrong.

Signed-off-by: Bill Traynor <wmat@riscv.org>

readme.adoc

@@ -24,7 +24,7 @@ To build the document, you'll need the following tools installed on your system:
 * asciiDoctor-pdf, asciidoctor-bibtex, asciidoctor-diagram and asciidoctor-mathematical
 * Docker
 
-=== Clonning the Repository
+=== Cloning the Repository
 
 `git clone --recurse-submodules https://github.com/riscv/docs-spec-template.git`
 
@@ -56,4 +56,4 @@ You can customize the build process by modifying the following variables in the
 * `DATE`: Specifies the revision date for the generated documentation. The default value is the current date.
 * `REVMARK`: Specifies the revision remark for the generated documentation. The default value is "Draft".
 * `PDF_RESULT`: Specifies the name of the output PDF file.
-* `DOCKER_RUN`: Defines the Docker run command used when Docker is available.
+* `DOCKER_RUN`: Defines the Docker run command used when Docker is available.