Filter introduction suggestions

[hunter2009]

After reading useage of filtering multiple times, I found some filter usage rules. It had three key elements and two operators: Elements list

• package-name
• dir-name
• git(commitId or branch)

Two operators

• ... ellipsis
• ^

element(except dir-name) and operators can be mixed, like this：<operators>{package-name}<operators>. It had 20 combinations like this:

only package-name:(just 1) 1.package-name

package-name with one operator(4 situations): 2. ...package-name 3. package-name... 4. ^package-name 5. package-name^

package-name with two operator(6 situations): 6. ...package-name... 7. ^package-name^ 8. ...^package-name, 9. ...package-name^ 10. package-name^... 11. ^package-name...

package-name with three operator(8 situations) ...balabala...

package-name with four operator(1 situations) ...^package-name^...

It's very interesting and easy to get all combinations. So I think filter can be grouped by elements and operators, it's a good way to learn.