redirecting stderr to /dev/null

stops an error if a user has never used clinte
removed outdated wording about make behavior
crate version bump
moved hashing to shellscript to check for posts

removes dependency on sha2 crate and allows users
to choose their own hashing algorithm easily.

now copies clinte.json to $HOME/.clinte.json once
the posts are viewed. a shellscript can be used to
compare the hash of the global clinte.json to the
hash of the copy. an example script is supplied.

on `make install` the example script is installed
to /etc/profile.d/, where it will be run for users
on login.
test for hashing bits
recording hash of posts file in homedir

This will facilitate checking for new posts on login.
including manifest for sourcehut builds
removed old packages from travis
changed upgrade steps

changed refs to v2.0.0 -> v2.x
install target: check for clinte.json before copying

removed upgrade target since it's now redundant
moved startup timer to end of execution, as run timer
updated usage for linewrap
configurable line wrapping (80 default)

disabled when set to a value below 10
removed tag checkout when building
clarified upgrade process and note section
testing create/delete
make test is now single-threaded
travis using single-threaded testing