feat(docs): reorganize Tech Radar sections for improved clarity and structure

Author: stefaniuk

docs/adr/tech-radar.md

@@ -1,12 +1,24 @@
 # Tech Radar
 
-- Python tech stack
-  - Python and dependency management: `uv`
-  - Linting and formatting: `ruff`
-  - Type checking: `mypy`
-  - Testing: `pytest`
-  - Logging: `structlog` or `Powertools for AWS Lambda`
-  - CLI argument parsing: `typer`
+## Python tech stack
+
+- Python and dependency management: `uv`
+- Linting and formatting: `ruff`
+- Type checking: `mypy`
+- Testing: `pytest`
+- Logging: `structlog` or `Powertools for AWS Lambda`
+- CLI argument parsing: `typer`
+
+## TypeScript tech stack
+
+- TypeScript and dependency management: Node.js (LTS) and `pnpm`
+- Linting and formatting: `biome`
+- Type checking: `tsc`
+- Testing: `vitest`
+- Logging: `winston` or `Powertools for AWS Lambda`
+- CLI argument parsing: `commander`
+
+Note: Selecting any default tool above still requires an ADR that compares and assesses at least two or three popular alternatives using the [ADR template](./adr-template.md).
 
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