Sequelize-typescript: Add a how-to deal-with-db-migrations to the docs

[RobinBuschmann]

As mentioned here #274 and due to https://github.com/sequelize/cli/issues/441#issuecomment-365920223 we should inform users of sequelize-typescript how to deal with db migrations.

[Toub]

After reading the related issues, I am not sure to understand if it is possible (and how) to use sequelize-cli to migrate sequelize-typescript models, or if we need to use a pure SQL script.

[ghost]

As per the linked issue's discussion I can write a blog post that details how to use one of two tools, or both if I feel super gouda.

I'll comment updates here as I go, and I can PR a link to the blog in the readme, or we can adapt it as a Wiki post in this github repo (idk how wikis work or if they're any good >.> - do they markdown? Are the SEO friendly?)

[RobinBuschmann]

Hey @sanewell92, sounds great. I prefer the readme or another versioned *.md file over github wiki :) Regarding SEO: I think github will do the job for us.

[vschoener]

@sanewell92 Sounds good :) Did you start something? :)

[ghost]

I'm officially moving my GitHub presence to the @snewell92 account. This won't confusing at all 😆

I have some time to continue the work I started; if you want to follow my progress this is the branch on a fork on the aforementioned account.

Feel free to check out commit ab0b57294e8c70ed5a5c0ffc12bb0d3177150caf for the deets.

[cjancsar]

@snewell92 did you ever make any progress on this? That branch is dead.

[tommymarshall]

We are looking to have this feature as well.