Delete phrases from all files recursively using linux

The following line deletes <!--# include file="header.html" --> in all files

find . -name "*.html" -exec sed -i 's|https://springfield-ohio-post|http://springfield-ohio-post|' {} \;


find . -type f -exec sed -i 's|</head>|<table border="15" cellpadding="12" cellspacing="2"></head>|g' {} +
THIS ONE DOES ALL FILE FORMATS