Fix \Rho (KaTeX#1870)

Author: riteme

docs/supported.md

@@ -122,8 +122,8 @@ $\allowbreak α β γ δ ϵ ζ η θ ι κ λ μ ν ξ o π \allowbreak ρ σ τ
 | $\Epsilon$ `\Epsilon` | $\Zeta$ `\Zeta` | $\Eta$ `\Eta` | $\Theta$ `\Theta`
 | $\Iota$ `\Iota` | $\Kappa$ `\Kappa` | $\Lambda$ `\Lambda` | $\Mu$ `\Mu`
 | $\Nu$ `\Nu` | $\Xi$ `\Xi` | $\Omicron$ `\Omicron` | $\Pi$ `\Pi`
-| $\Sigma$ `\Sigma` | $\Tau$ `\Tau` | $\Upsilon$ `\Upsilon` | $\Phi$ `\Phi`
-| $\Chi$ `\Chi` | $\Psi$ `\Psi`| $\Omega$ `\Omega`
+| $\Rho$ `\Rho` | $\Sigma$ `\Sigma` | $\Tau$ `\Tau` | $\Upsilon$ `\Upsilon`
+| $\Phi$ `\Phi` | $\Chi$ `\Chi` | $\Psi$ `\Psi` | $\Omega$ `\Omega`
 | $\varGamma$ `\varGamma`| $\varDelta$ `\varDelta` | $\varTheta$ `\varTheta` | $\varLambda$ `\varLambda`  |
 | $\varXi$ `\varXi`| $\varPi$ `\varPi` | $\varSigma$ `\varSigma` | $\varUpsilon$ `\varUpsilon` |
 | $\varPhi$ `\varPhi`  | $\varPsi$ `\varPsi`| $\varOmega$ `\varOmega` ||

src/macros.js

@@ -864,7 +864,7 @@ defineMacro("\\Rarr", "\\Rightarrow");
 defineMacro("\\real", "\\Re");
 defineMacro("\\reals", "\\mathbb{R}");
 defineMacro("\\Reals", "\\mathbb{R}");
-defineMacro("\\Rho", "\\mathrm{R}");
+defineMacro("\\Rho", "\\mathrm{P}");
 defineMacro("\\sdot", "\\cdot");
 defineMacro("\\sect", "\\S");
 defineMacro("\\spades", "\\spadesuit");