add count parameter to limit output

[cmeury]

adding flag: -c, --count int The amount of resources to include

Outputting only the first count resources, after applying all other filters. Output everything in the following cases:

• default value 0
• negative value
• count larger than length of filtered resources

Wanted to add this for convenience when using it interactively for testing purposes. Not a daily golang programmer, please be frank with comments.