[Doc][Installaton] Add details and recommendations for EC2

## Documentation Scope
Getting started manual can have diverse ways to setup DevLake via EC2 etc. This will also help in discoverability.

## Describe the Change
- Add recommended EC2 instance configurations for small scale, large scale, etc.
- Below is the example of how it can look (refer snapshot below)

Use-case | Instance | CPU | Memory
| :-----: | :-----: | :-----: | :-----: |
Proof of Concept | t3.medium | 2 CPU | 8 GB
(Add more) |

## Screenshots

## Additional context
We can also add docs for similar installation methods such as GCP etc.