update changelog for v0.6.0

build: go, dependency upgrades

fix: replace 'omm' with 'hours' in errors (#45)

ci: add missing permissions for release step

feat: shift time with j/k; relative timestamps

Allows time to be changed in the "Task Log Entry View" to be moved
forwards/backwards via j/k respectively. Timestamps in "Task Log" view
show up differently, depending on whether the end timestamp falls on
today/yesterday/in the current week/before.

feat: add gen subcommand

feat: add initial help message