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- [x] Add new / update outdated documentation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: joblib
  version: 1.1.0

requirements:
  run:
    - distutils

source:
  url: https://files.pythonhosted.org/packages/92/b9/9e3616e7e00c8165fb25175c53444533bdde05f3e974d45d9fcbbe451ee6/joblib-1.1.0.tar.gz
  sha256: 4158fcecd13733f8be669be0683b96ebdbbd38d23559f54dca7205aea1bf1e35

test:
  imports:
    - joblib

package:
  name: joblib
  version: 1.1.0

requirements:
  run:
    - distutils

source:
  url: https://files.pythonhosted.org/packages/92/b9/9e3616e7e00c8165fb25175c53444533bdde05f3e974d45d9fcbbe451ee6/joblib-1.1.0.tar.gz
  sha256: 4158fcecd13733f8be669be0683b96ebdbbd38d23559f54dca7205aea1bf1e35

test:
  imports:
    - joblib
