Merge pull request nushell#755 from coolshaurya/cd-command-docs

Make docs for the cd command

Author: andrasio

docs/commands/cd.md

@@ -0,0 +1,25 @@
+# cd
+
+If you don't know about it already, the `cd` command is very simple. It stands for 'change directory' and it does exactly that. It changes the current directory that you are in to the one specified. If no directory is specified, it takes you to the home directory. Additionally, `..` takes you to the parent directory
+
+## Examples -
+
+```shell
+/home/username> cd Desktop
+/home/username/Desktop> now your current directory has been changed
+```
+
+```shell
+/home/username/Desktop/nested/folders> cd ..
+/home/username/Desktop/nested> cd ..
+/home/username/Desktop> cd ../Documents/school_related
+/home/username/Documents/school_related> cd ../../..
+/home/>
+```
+
+```shell
+/home/username/Desktop/super/duper/crazy/nested/folders> cd
+/home/username> cd ../../usr
+/usr> cd
+/home/username> 
+```