Add `!iknow` and `!theyknow`

[tiffafoo]

Detailed Description

!iknow add a self-summary of what languages/techs the user knows.
!they know @someone responds with a list of skills the user specified knows.

There are different ways to implement this. Either:

• A poll type message that the user can react to
• They send a comma-separated list of skills that will get added to our table + bridging table (easiest in my opinion)

Context

• !iknow JavaScript => !theyknow @sirMerr => Bot responds with:@sirMerr knows JavaScript
• !iknow 'Web Dev', Ruby => !theyknow @sirMerr => Bot responds with:

  |@sirMerr knows
  |  * Web Dev
  |  * Ruby
  

Possible Implementation

Pseudo code

SQL

INSERT INTO techs (id, name) VALUES (DEFAULT, [name_here]) 
  ON CONFLICT DO NOTHING 
  RETURNING id; 
...
-- ON CONFLICT DO NOTHING could also be added in the following query
INSERT INTO accounts_techs (account, tech) VALUES ([account_id_here], [tech_id_here]);

insertTech(
    discordId,
    callback = data => {},
    error = err => {
        console.log(err);
        msg.channel.send('Could not insert tech');
    }
)