fix "extention" typo (#1103)

replaces all appearances of "extention" with "extension"

.local/bin/compiler

@@ -4,7 +4,7 @@
 # have this script run via vim.
 #
 # Compiles .tex. groff (.mom, .ms), .rmd, .md, .org.  Opens .sent files as sent
-# presentations. Runs scripts based on extention or shebang.
+# presentations. Runs scripts based on extension or shebang.
 #
 # Note that .tex files which you wish to compile with XeLaTeX should have the
 # string "xelatex" somewhere in a comment/command in the first 5 lines.

.local/bin/queueandnotify

@@ -2,7 +2,7 @@
 
 # Podboat sucks. This script replaces it.
 # It reads the newsboat queue, queuing downloads with taskspooler.
-# It also removes the junk from extentions.
+# It also removes the junk from extensions.
 queuefile="${XDG_DATA_HOME:-$HOME/.local/share}/newsboat/queue"
 
 while read -r line; do