add contributing to issues (#118)
add contributing to issues (#118)

Signed-off-by: Brandon Lum <3f6482c5eb7fd38182f7c556102c9a320d585f85@gmail.com>

Signed-off-by: Brandon Lum <3f6482c5eb7fd38182f7c556102c9a320d585f85@gmail.com>
guacsec/guac