Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/sys.md

@@ -1,50 +1,19 @@
-# sys
+---
+title: sys
+layout: command
+version: 0.59.0
+---
 
-This command gives information about the system nu is running on.
+View information about the system.
+
+## Signature
+
+```> sys ```
 
 ## Examples
 
+Show info about the system
 ```shell
 > sys
-─────────┬─────────────────────────────────────────
- host    │ [row 7 columns]
- cpu     │ [row cores current ghz max ghz min ghz]
- disks   │ [table 4 rows]
- mem     │ [row free swap free swap total total]
- net     │ [table 19 rows]
- battery │ [table 1 rows]
-─────────┴─────────────────────────────────────────
 ```
 
-```shell
-> sys | get host
-──────────┬──────────────────────────────────────────────────────────────────────────────────────────────────
- name     │ Darwin
- release  │ 19.5.0
- version  │ Darwin Kernel Version 19.5.0: Tue May 26 20:41:44 PDT 2020; root:xnu-6153.121.2~2/RELEASE_X86_64
- hostname │ Josephs-MacBook-Pro.local
- arch     │ x86_64
- uptime   │ 5:10:12:33
- sessions │ [table 2 rows]
-──────────┴──────────────────────────────────────────────────────────────────────────────────────────────────
-```
-
-```shell
-> sys | get cpu
-─────────────┬────────
- cores       │ 16
- current ghz │ 2.4000
- min ghz     │ 2.4000
- max ghz     │ 2.4000
-─────────────┴────────
-```
-
-```shell
-> sys | get mem
-────────────┬─────────
- total      │ 68.7 GB
- free       │ 11.1 GB
- swap total │ 0 B
- swap free  │ 0 B
-────────────┴─────────
-```