Super minimal shell bookmarking.
m [bookmark]: will create a bookmark with name "[bookmark]"
g [bookmark]: will cd to directory bookmark (if "[bookmark]" is defined).
g [bookmark]/[subdir]: will cd to directory bookmark, then cd to the subdir(s) after the slash.
savemarks: will write the marks to
$HOME/.shmarks. When you source
shmark.sh, it'll load global marks from