Update to readme to include to common questions in FAQ

[satyavel]

Answering two common questions we get: What unique benefits do you get with Bicep? Why not use a programming language?

Contributing a Pull Request

If you haven't already, read the full contribution guide. The guide may have changed since the last time you read it, so please double-check. Once you are done and ready to submit your PR, run through the relevant checklist below.

Contributing to documentation

• The contribution does not exist in any of the docs in either the root of the docs directory or the specs

Contributing an example

• I have checked that there is not an equivalent example already submitted
• I have resolved all warnings and errors shown by the Bicep VS Code extension
• I have checked that all tests are passing by running dotnet test
• I have consistent casing for all of my identifiers and am using camelCasing unless I have a justification to use another casing style

Contributing a feature

• I have opened a new issue for the proposal, or commented on an existing one, and ensured that the Bicep maintainers are good with the design of the feature being implemented
• I have included "Fixes #{issue_number}" in the PR description, so GitHub can link to the issue and close it when the PR is merged
• I have appropriate test coverage of my new feature