Fix the page locator of the ISLR citation for the reducible error #303

_subfiles/_rem-reducible-risk-notes.qmd (added in #291) says:

@james2021islr2e [Section 2.1.1, p. 18] calls the squared difference between a prediction function and the conditional mean the "reducible error".

I checked it against An Introduction to Statistical Learning with Applications in R, 2nd edition (the corrected June 2023 PDF; page numbers are the printed ones):

• Section 2.1.1 "Why Estimate f?" starts on p. 17.
• The term "reducible error" is introduced on p. 18: "The accuracy of Y^ as a prediction for Y depends on two quantities, which we will call the reducible error and the irreducible error."
• The squared difference itself, [f(X) - f^(X)]^2, is labelled "Reducible" in equation (2.3) on p. 19.

So the locator "p. 18" gives the name but not the squared difference the sentence attributes to it.
Change the locator to "Section 2.1.1, pp. 18--19" (or "Section 2.1.1, Eq. 2.3, p. 19").

Found while checking the citation for the review of pds#291.

Posted by Claude Code (AI agent) --- not written by a human.