fix base-10 assumption in note

spec.html

@@ -2244,7 +2244,7 @@ <h1>
           <emu-note>
             <p>For implementations that provide more accurate conversions than required by the rules above, it is recommended that the following alternative version of step <emu-xref href="#step-number-tostring-intermediate-values"></emu-xref> be used as a guideline:</p>
             <emu-alg replaces-step="step-number-tostring-intermediate-values">
-              1. Otherwise, let _n_, _k_, and _s_ be integers such that _k_ &ge; 1, 10<sup>_k_ - 1</sup> &le; _s_ &lt; 10<sup>_k_</sup>, 𝔽(_s_ &times; 10<sup>_n_ - _k_</sup>) is _x_, and _k_ is as small as possible. If there are multiple possibilities for _s_, choose the value of _s_ for which _s_ &times; 10<sup>_n_ - _k_</sup> is closest in value to ℝ(_x_). If there are two such possible values of _s_, choose the one that is even. Note that _k_ is the number of digits in the decimal representation of _s_ and that _s_ is not divisible by 10.
+              1. Otherwise, let _n_, _k_, and _s_ be integers such that _k_ &ge; 1, _radix_<sup>_k_ - 1</sup> &le; _s_ &lt; _radix_<sup>_k_</sup>, 𝔽(_s_ &times; _radix_<sup>_n_ - _k_</sup>) is _x_, and _k_ is as small as possible. If there are multiple possibilities for _s_, choose the value of _s_ for which _s_ &times; _radix_<sup>_n_ - _k_</sup> is closest in value to ℝ(_x_). If there are two such possible values of _s_, choose the one that is even. Note that _k_ is the number of digits in the representation of _s_ using radix _radix_ and that _s_ is not divisible by _radix_.
             </emu-alg>
           </emu-note>
           <emu-note>