Correct typos

 codespell -L 'tothe,mesures' -S './texmf,*.eps,*.tlg,*-v2.dtx'

CHANGELOG.md

@@ -339,7 +339,7 @@ Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to
 - Options `digit-group-size`, `digit-group-first-size` and
   `digit-group-other-size` to control digit grouping
 - Options `display-per-mode` and `inline-per-mode` to offer additional
-  flexiblity in `per-mode` control
+  flexibility in `per-mode` control
 - Option `per-symbol-script-correction`
 - Option `power-half-as-sqrt`
 - Option `retain-negative-zero`
@@ -1396,7 +1396,7 @@ Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to
 - Allow for `bidi`/RTL when applying `\text`
 - Search-and-replace in UTF-8 literal units
 - Load binary-units only when requested (issue [\#201](https://github.com/josephwright/siunitx/issues/201))
-- Disable `\hightlight` in bookmarks (issue [\#207](https://github.com/josephwright/siunitx/issues/207))
+- Disable `\highlight` in bookmarks (issue [\#207](https://github.com/josephwright/siunitx/issues/207))
 
 ## [v2.5l] - 2012-11-21
 

siunitx-abbreviation.dtx

@@ -40,7 +40,7 @@
 % \GetFileInfo{siunitx.sty}
 %
 % \title{^^A
-%   \pkg{siunitx-abbreviations} -- Abbreviatons^^A
+%   \pkg{siunitx-abbreviations} -- Abbreviations^^A
 %   \thanks{This file describes \fileversion,
 %     last revised \filedate.}^^A
 % }

siunitx-unit.dtx

@@ -272,7 +272,7 @@
 % \end{variable}
 %
 % \begin{variable}{\l_siunitx_unit_fraction_tl}
-%    The fraction function which is applied whne constructing fractional units:
+%    The fraction function which is applied when constructing fractional units:
 %    set by |fraction-command|.
 % \end{variable}
 %