Add quickstart and improve description

Author: CrazyPython

README.md

@@ -4,17 +4,40 @@
 
 Tree query is a tool that searches across indented lines.
 
-It is a replacement for Roam's query system.
+It is a replacement for Roam's query system. It supports everything Roam does, except for block references.
 
-## Command-line usage
+## Quickstart
 
-`tree-query '{and: [[Hello]] [[Hi]]}' file1 file2 folder1 folder2`
+**Query in current directory:**
+```
+tree-query '{and: [[Page 1]] [[Page 2]]}' .
+```
+[*Learn to navigate to a working directory with `cd`*](https://linuxize.com/post/linux-cd-command/)
+
+**Query in a folder:**
+
+```
+tree-query '{and: [[Page 1]] [[Page 2]]}' /Users/steve/myfoldername/
+```
+*Learn to get the location of a folder on [macOS](https://osxdaily.com/2009/11/23/copy-a-files-path-to-the-terminal-by-dragging-and-dropping/), [Windows](https://www.top-password.com/blog/copy-full-path-of-a-folder-file-in-windows/), or [GNU+Linux](https://unix.stackexchange.com/questions/102551/mouse-shortcut-to-copy-the-path-to-a-file-in-the-gnome-file-manager).*
+
+**Query in a group of folders and files:**
+
+```
+tree-query '{and: [[Page 1]] [[Page 2]]}' /Users/steve/myfoldername/ file1
+```
+
+**Query stdin:**
+
+```
+cat myfile | tree-query '{and: [[Page 1]] [[Page 2]]}'
+```
 
 ## Features
 
 This section is a work-in-progress.
 
-* **Fast**: Over 880Mbps on a MacBook Air
+* **Fast**
 
 ## Contributing