[bootlin/training-materials] a930c7: yocto: slides: fix broken URL to Yocto's git repo

[tleb]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: a930c74ebe513d0ef06f0affd0f29e2a694859a3
      https://github.com/bootlin/training-materials/commit/a930c74ebe513d0ef06f0affd0f29e2a694859a3
  Author: Théo Lebrun <theo.lebrun at bootlin.com>
  Date:   2022-07-18 (Mon, 18 Jul 2022)

  Changed paths:
    M slides/yocto-overview/yocto-overview.tex

  Log Message:
  -----------
  yocto: slides: fix broken URL to Yocto's git repo

Signed-off-by: Théo Lebrun <theo.lebrun at bootlin.com>