Docs enhancements for empathy-sessions and others

[dpordomingo]

These are many improvements made to the docs considering different inputs; each case is separated in a different commit.

In case you want to exclude any of the changes, or discuss in a separate PR, just say so and I'll extract it.

from empathy sessions (Miguel's#28, Michael's#31, Juanjo's#24, ):

• 6a2c509 Documment config.yml.tpl main keys
• a8b7144 When running source{d} Lookout with docker-compose, the default LOG_LEVEL is error
• 399f7c7 Explain how to reload the config file.
• 708bb9e Explain how to pass a valid GitHub user/token in Quickstart; what happens when source{d} Lookout is running properly and how to know it;

from TeamFocusMeeting

• 9467e1f Explain the external dependencies: PostgreSQL, bblfsh and RabbitMQ.

from "new" PRs

• 7207e2e Documment how to run web interface (not yet exposed in SUMMARY.md)
• b2fa812 Explain how to fetch data from DataService and filter by language Add filter by languages to data server requests lookout-sdk#44
• e70e906 lookout-sdk will exit with error if analyzer failed as done by feature: make lookout-sdk return error code if analysis failed #411

other

• db0ae73 Separate the two config methods: config.yml and .lookout.yml
• 225bb49 Avoid user commiting .pem keys
• 5519b73 Remove anchors that are not supported by GitBook
• a1ebe26 Complete the explanation about how to use GitHub App authentication

[carlosms]

what is TFM?

[dpordomingo]

Team Focus Meeting (applications/2018-12-18-app-team-focus.md)

[carlosms]

I have to say, smaller PRs would be much easier to review

[carlosms]

Link does not work, at least in GitHub, I don't know about Gitbook.

Suggested change

	- [`config.yml`](#config.yml), to define the global configuration of the server.
	- [`config.yml`](#configyml), to define the global configuration of the server.

[dpordomingo]

I asumed GitBook as the preferred way to render our docs, and it works differently when creating anchors for titles having . inside.

• Title: config.yml
• GitBook: #config-yml
• GitHub: #configyml

In case it is required to support both, would you propose an alternative?

[carlosms]

For this PR it would be fine if it only works on GitBook, in my opinion. But if the section links do not work on GitHub let's at least open an issue and try to fix it at some point. Maybe we just need to assume the limitations and avoid . in titles.

[dpordomingo]

agree, issue created #469

[smacker]

There are 2 points I think we should change but because Carlos already mentioned and tracks them I approve.

[dpordomingo]

Thanks @carlosms for your detailed review (and sorry for making a big PR 😉)
I had to rebase to work over the new master (in order to take some of your latest changes, and also some from Vadim)
Your suggestions were addressed by 518d15f

Pending things that requires your feedback:

• Do we have a link for the babelfish proxy methods? @discussion_r246323093
• Anchors to titles with . inside (#config-yml vs #configyml for config.yml title) @discussion_r246331372