Dockerfiles: Install the mermaid CLI

In order to include mermaid diagrams that are both github and asciidoc
compatible, we need to include the mermaid-cli package.

With that CLI, we can convert github mermaid diagrams on the fly, as
shown in riscv-non-isa/riscv-ap-tee-io#43

Signed-off-by: Samuel Ortiz <[email protected]>

Dockerfiles/ubuntu2204

@@ -56,5 +56,5 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     rghost \
     rouge \
     ruby_dev && \
-    npm install -g [email protected] [email protected]
+    npm install -g [email protected] [email protected] @mermaid-js/mermaid-cli@9