Add Features and Usage sections

README.md

@@ -7,6 +7,47 @@ the sysinfo crate has gone too far...
 
 Written just for fun.
 
+## Features
+- Query about:
+    - CPU
+    - Sensors
+    - Memory
+    - Swap memory
+    - Disks
+    - OS
+- Multiple queries can be issued (`dshw memory total usage available free`)
+- Custom delimiter is supported (`dshw -d ', ' drive /dev/sda3 total available usage fs mount-point`)
+
+## Usage
+To print total and available memory:
+```
+~ $ dshw memory total available
+16689270784
+10336894976
+```
+
+Some commands like `cpu`, `sensor` or `drive` take a name/id as the first required argument:
+```
+~ $ dshw drive /dev/sda3 usage total
+ext4
+259652198400
+474853687296
+```
+
+Some commands take zero arguments:
+```
+~ $ dshw cpu-arch
+x86_64
+```
+
+You can also specify a desired delimiter:
+```
+~ $ dshw -d ', ' list-cpus
+cpu0, cpu1, cpu2, cpu3, cpu4, cpu5, cpu6, cpu7, cpu8, cpu9, cpu10, cpu11, cpu12, cpu13, cpu14, cpu15
+```
+
+Type `dshw help` to see all commands. Type, for example, `dshw help os` to see all os-related subcommands.
+
 ## Installation
 You'll need the Rust toolchain ([rustup](https://rustup.rs/) or from system package repo) and make
 sure it's up to date.
@@ -22,7 +63,7 @@ To see all available options, pass `-h`, `--help` or `help`.
 ## TODO
 - [ ] Add extra functionality like network.
 - [ ] Timing: measure stats within specified interval.
-- [ ] Add format option: something like `dshw drive '/dev/sda3' fmt '{usage}/{total} GiB'`
+- [ ] Add format option: something like `dshw drive /dev/sda3 fmt '{usage}/{total} GiB'`
 
 ...