docs: updates taskell.app readme

docs/html/index.md

@@ -49,8 +49,6 @@ You can install Taskell on your Mac using [Homebrew](https://brew.sh):
 brew install taskell
 ```
 
-There are usually bottles (binaries) available. If these are not available for your computer, Homebrew will build Taskell from scratch, which can take a while, particularly on older machines. Occasionally the build fails the first time, but usually works on a second attempt.
-
 ### Debian/Ubuntu
 
 [A `.deb` package is available for Debian/Ubuntu](https://github.com/smallhadroncollider/taskell/releases). Download it and install with `dpkg -i <package-name>`. You may also need to install the `libtinfo5` package (`sudo apt install libtinfo5`).
@@ -280,6 +278,16 @@ You shouldn't try to assign the `1`-`9` keys, as it will not overwrite the defau
 
 Due dates must be input with the format `YYYY-MM-DD` or `YYYY-MM-DD HH:MM`. The date will not be accepted otherwise.
 
+You can also pass in relative times such as `1w 2d` (for 1 week and 2 days). Valid units are:
+
+- `s` (seconds)
+- `m` (minutes)
+- `h` (hours)
+- `d` (days)
+- `w` (weeks)
+
+These can be used in any combination. If the time is made up only of days and/or weeks, the due date will not include a time.
+
 By default times are stored in the Markdown file as UTC. If you would like local times (and are unlikely to open the file in lots of different timezones) then you can set `localTimes` to `true` in the `markdown` section of the [config file](#configuration). If you have this setting on and you change timezone, you'll get a diff on all your times the next time you make changes to the file.