Documentation should make it clear how to get started

Reading the home page of the project:

```
Samples. There are a couple of samples available, showing possible scenarios to use TestMyBot. For all samples, you these commands to run them:

> npm install
> npm run test

```
I would suggest three initial fixes:

* Fix this typo: "For all samples, you these commands to run them:" --> "For all samples, you should type these commands to run them:"

* What kind of test will it launch the first time? I mean, for the Facebook Messenger (fbdirect) case, if I understand correctly, you first must edit testmybot.json with your FB credentials and FB Page ID of the bot, then execute `npm run emulator` to create and save a conversation and finally, you type `npm run test` to automatically run the conversation again, this time as a test (output expected vs. output received). However, it seems that there is an already created conversation there:
`testmybot/samples/fbdirect/spec/convo/simplecalc.convo.txt`. I think that this is for testing the [sample bot provided with botium](https://github.com/codeforequity-at/testmybot-sample-calculator), isn't it? But I'm a little bit confused here. Could you clarify this in the markdown text?

* The [markdown for the FBdirect page](https://github.com/codeforequity-at/testmybot/tree/master/samples/fbdirect) links to an outdated article. For example, in "Step 2" it suggest to run `node node_modules/testmybot-chat/index.js` but that directory is not there anymore (it's called testmybot, not testmybot-chat) and (please, correct me if I am wrong) the emulator is not longer launched with that command but with this one:
```
> npm install
> npm run emulator

```
Could it be possible to copy the text from chatbotsmagazine.com article in a wiki page so we can propose pull requests to update it (and keep it updated)?

This kind of small documentation fixes could help onboarding project newcomers (like myself!)