apg: add page (#1013)

* add page with examples for apg (advanced password generator)
* edits per code review
* spread the examples across more options than just -m and -M
* expand abbreviations and add double curly brackets

pages/common/apg.md

@@ -0,0 +1,23 @@
+# apg
+
+> Creates arbitrarily complex random passwords.
+
+- Create random passwords (default password length is 8):
+
+`apg`
+
+- Create a password with at least 1 symbol (S), 1 number (N), 1 uppercase (C), 1 lowercase (L):
+
+`apg -M SNCL`
+
+- Create a password with 16 characters:
+
+`apg -m {{16}}`
+
+- Create a password with maximum length of 16:
+
+`apg -x {{16}}`
+
+- Create a password that doesn't appear in a dictionary (the dictionary file has to be provided):
+
+`apg -r {{dictionary_file}}`