(cli tool): make cdk init default to typescript

### Describe the feature

Seeing as typescript is the primary language for AWS CDK, I think it makes sense that `cdk init` defaults to `cdk init --language=typescript`.

In general I think AWS CDK is a wonderful solution to manage infrastructure in the age of LLMs, and as someone who uses it often to manage infrastructure for personal projects, not having this default is frustrating. If we see a future where AWS CDK becomes a standard for chill personal projects, not just big-scale enterprise projects, I think this change will save a lot of collective developer time.

What are you guys' thoughts?

I first started a discussion at #35774 - I closed the discussion after copying the details here since that seems to be more of a Q&A environment

### Use Case

I'm always frustrated typing 'cdk init' only to get a error message and then have to type `npx cdk init --language=typescript`

I use cdk a lot for my personal projects, so this happens often

### Proposed Solution

`cdk init` defaults to `cdk init --language=typescript`

### Other Information

_No response_

### Acknowledgements

- [x] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### AWS CDK Library version (aws-cdk-lib)

aws-cdk-lib@2.179.0

### AWS CDK CLI version

2.1000.2

### Environment details (OS name and version, etc.)

MacOS

Start at the cdk init CLI entry point and trace how the language option is selected when no language is supplied. Confirm the expected behavior and check the CLI's existing init coverage; done means bare cdk init uses the TypeScript template without requiring an explicit language option.

Written by the indexing model from the issue text.