docs: fix misspellings

Fix several misspellings in documentation and config comments detected by `misspell`.

.markdownlint.yml

@@ -1,6 +1,6 @@
 default: true
 
-# Use specific styles, to be consistent accross all documents.
+# Use specific styles, to be consistent across all documents.
 # Default is to accept any as long as it is consistent within the same document.
 heading-style: # MD003
   style: atx
@@ -48,12 +48,12 @@ link-fragments: false # MD051
 #   https://gohugo.io/content-management/syntax-highlighting/#languages
 #   https://docs.github.com//get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting
 # In addition, we only want to allow identifiers (aliases) that correspond to
-# the same language in Hugo and GitHub, and preferrably also VSCode and other
+# the same language in Hugo and GitHub, and preferably also VSCode and other
 # commonly used tools, to avoid confusion. An example of this is that "shell"
 # by some are considered an identifier for shell scripts, i.e. an alias for
 # "sh", while others consider it an identifier for shell sessions, i.e. an
 # alias for "console". Although Hugo and GitHub in this case are consistent and
-# have choosen the former, using "sh" instead, and not allowing use of "shell",
+# have chosen the former, using "sh" instead, and not allowing use of "shell",
 # avoids the confusion entirely.
 fenced-code-language: # MD040
   allowed_languages: