Fix codespell failures in papers/wg21-latex

Fix genuine typos (souces, intializers) and add the legitimate
technical tokens "FitH" (a PDF pdfstartview keyword) and "ist" (the
makeindex style-file extension) to codespell's ignore list, since
they're false positives rather than misspellings.

Author: steve-downey

papers/wg21-latex/README.md

@@ -8,7 +8,7 @@ SPDX-License-Identifier: 2.0 license with LLVM exceptions
 
 Compiling the paper requires a working LaTeX installation. See instructions for configuring your system at [C++ Standard Draft Sources](https://github.com/cplusplus/draft/blob/main/README.rst)
 
-The papers/ subdirectory has the LaTeX souces for P2988 and the supporting macro definitions. To build, run
+The papers/ subdirectory has the LaTeX sources for P2988 and the supporting macro definitions. To build, run
 
 ```shell
 make papers

papers/wg21-latex/xrefdelta.tex

@@ -454,7 +454,7 @@
 % CWG 2843 removed [uaxid.def.rfmt]
 \removedxref{uaxid.def.rfmt}
 
-% P3016R6 Resolve inconsistencies in begin/end for valarray and braced intializers
+% P3016R6 Resolve inconsistencies in begin/end for valarray and braced initializers
 \removedxref{support.initlist.range}
 
 %%% Renamed sections.

pyproject.toml

@@ -15,4 +15,4 @@ dev = [
 ]
 
 [tool.codespell]
-ignore-words-list = 'unexpect'
+ignore-words-list = 'unexpect,fith,ist'