Warn Module update + started documentation + added guild aware permission checking

[GiregL]

Warn module:

• added !popwarn command
• added warn and unwarn roles (for permission checking)
• added log channel in configuration
• added logs for each action (excluding warnlist)

Documentation:

• created summary
• created Warn Module doc
• API documentation will come later

Bot modification:

• Added new field to modules: GuildAwarePrivilegeCheck
• Made PrivilegeCheck and GuildAwarePrivilegeCheck complementary, both of them should pass to check privileges
• GuildAwarePrivilegeCheck takes the guild and the member as parameters, enabling configuration dependent privilege checking