Building on macOS Sonoma

I am unable to build on macOS Sonoma following the guides https://github.com/funcool/clojurescript-unraveled/issues/134 and https://github.com/funcool/clojurescript-unraveled/issues/153. I am getting the following error.

```
% make pdf
mkdir -p dist/
asciidoctor -b docbook45 -a numbered -d book -a data-uri! src/index.adoc -o dist/clojurescript-unraveled.xml
asciidoctor: FAILED: missing converter for backend 'docbook45'. Processing aborted.
Use --trace to show backtrace
make: *** [docbook] Error 1
```

I was able to generate PDF using [asciidoctor-pdf](https://github.com/asciidoctor/asciidoctor-pdf).

```
% sudo gem install asciidoctor-pdf
# had to use this version to get the installation to succeed
# sudo gem install css_parser -v 1.12.0
```

Then run `asciidoctor-pdf src/index.adoc`. This will create index.pdf file.

[ClojureScript Unraveled (3rd edition).pdf](https://github.com/funcool/clojurescript-unraveled/files/14474387/ClojureScript.Unraveled.3rd.edition.pdf)

You could have generated the PDF and other version in the repo so that each person doesn't have to build the file.

Thank you for the book!