BLD Add DISTDIR variable. ### Description

Adds `DISTDIR` env variable that points to the directory where libraries should be copied to when building shared libraries with recipe.

### Checklists

- [x] Add new / update outdated documentation

package:
  name: pydantic
  version: 1.10.2
  top-level:
    - pydantic
source:
  sha256: 91b8e218852ef6007c2b98cd861601c6a09f1aa32bbbb74fab5b1c33d4a1e410
  url: https://files.pythonhosted.org/packages/7d/7d/58dd62f792b002fa28cce4e83cb90f4359809e6d12db86eedf26a752895c/pydantic-1.10.2.tar.gz
requirements:
  run:
    - typing-extensions
about:
  home: https://github.com/samuelcolvin/pydantic
  PyPI: https://pypi.org/project/pydantic
  summary: Data validation and settings management using python type hints
  license: MIT

package:
  name: pydantic
  version: 1.10.2
  top-level:
    - pydantic
source:
  sha256: 91b8e218852ef6007c2b98cd861601c6a09f1aa32bbbb74fab5b1c33d4a1e410
  url: https://files.pythonhosted.org/packages/7d/7d/58dd62f792b002fa28cce4e83cb90f4359809e6d12db86eedf26a752895c/pydantic-1.10.2.tar.gz
requirements:
  run:
    - typing-extensions
about:
  home: https://github.com/samuelcolvin/pydantic
  PyPI: https://pypi.org/project/pydantic
  summary: Data validation and settings management using python type hints
  license: MIT
