Escape is needed for some patterns, specifically including dollar marks.

[LumaKernel]

Example:

  /dummy/2:
    put:
      summary: "simple"
      responses:
        202:
          description: "accept"
  /dummy/$2:
    put:
      summary: "simple"
      responses:
        202:
          description: "accept"

related: aspida/aspida#724 (not the same)