docs: improve style in Creating & Modifying pages (#24987)
docs: improve style in Creating & Modifying pages (#24987)

Co-authored-by: LB <8468275f0d120527324004754c3d088324306866@gatsbyjs.com>
Co-authored-by: Marcy Sutton <63f38fb7a2c9e72439a06d93cefb66621e8fc496@gatsbyjs.com>
Co-authored-by: gatsbybot <313a651c59fdaade90d152972001707d94b0975c@gmail.com>
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