Would be nice to have a section on 'Tables'

[mk4111]

I can see that there's a section on commands, but to follow through with the flow of a tutorial I think it would be super nice to have a section that described the following...:

• The general concepts of a table (columns, rows, etc.)
• How the above applies to Postgres.
• How to add and delete table
• How to add, delete, update columns
• What column and table constraints are

... in a way that allowed users to have a 'complete' table by the end of that section (and the two sections (on adding a user + database) before it).

[mk4111]

...added and removed the label because I didn't know if it was 'on me' to add them on the official dwyl repo...! Sorry!!