Proposal for adding developer oriented Makefile example

[staticaland]

My dream is to use codebraid to write README.md files for all my
projects.

To achieve this I have come up with a Makefile to convert all .cbmd
files in a repository. This makes it much easier to get up and running
with a more automated workflow. I feel it is a must to convince all my
programmer friends that using Codebraid for this purpose is awesome. I
would love to see literate programming reach a wider audience.

I have been exploring the possibilites in this repo if you are curious.

Would you be interested in a PR with an example for this workflow?
Perhaps as a subfolder in the examples directory.

Makefile:

CODEBRAID_DOCS := $(shell find . -name '*.cbmd')
MARKDOWN_DOCS = $(CODEBRAID_DOCS:.cbmd=.md)

.PHONY: cbmd watch

# Must cd into the target file directory so Pandoc and Codebraid are
# able to use relative paths as one would expect
%.md : %.cbmd
	cd $(@D); codebraid pandoc --from markdown --to gfm --filter=mermaid-filter --output $(notdir $@) --overwrite $(notdir $^)

cbmd : $(MARKDOWN_DOCS)

watch :
	find . -name '*.cbmd' | entr make cbmd