Resolves #157 without changing default behavior

[lazypower]

Now accepts an optional argument, eg:

$ make build doc=authors-interfaces.md
PYTHONPATH="/home/charles/workspace/juju/docs/tools/plugins:/home/charles/workspace/juju/docs/tools/plugins/gfm:" tools/build-from-source authors-interfaces.md
Converting authors-interfaces.md

I think having a single target is fine for the build action, however I'm +1 for adding a watch target, and already have phaux solution in place for that.

pip install watchdog

then follow that with

watchmedo shell-command   --patterns="*.md;"   --recursive   --command='make doc=$(basename ${watch_src_path})' .

Resolves #157

[marcoceppi]

Instead of duplicating code in the if switch, can you just make a bash method in the build-from-source file that can be used in the if statement or the for loop?

[JoshStrobl]

Rather than having two duplicate build commands, why don't we put the argument we passed (the file) into an array (equal to f) and have an else statement (for when there is no arg) that fetches all MD files and puts it into the array.

Example code below:

if [ "$1" ]; then
  f=("src/en/$1")
else
  f=$(find src/en/ -type f -name "*.md")
fi

for file in $f; do
  build $file
done

[lazypower]

Ok, cleaned up the bash file, created a tools/watch.sh to do the incremental building with 'make watch' - since there's no ubuntu package, added an echo about how to get watchdog installed if you're missing the watchmedo command.

[JoshStrobl]

I'm not entirely familiar with the watcher command syntax that was used, but there isn't anything glaring out at me that'd be an issue, so LGTM.

[lazypower]

for future people that find this: https://pypi.python.org/pypi/watchdog - look under Shell Utilities