Please help me how can i add my custom abc.css and filename.js in magento 2.2.2 .
default_header_html.xmldefault_header_html.xml
file path
app/design/frontend/custom-theme/my-first-theme/Magento_Theme/layout/default_header_html.xml
app/design/frontend/custom-theme/my-first-theme/Magento_Theme/layout/default_header_html.xml
my css path
app/design/frontend/custom-theme/my-first-theme/web/css/source/abc.css
app/design/frontend/custom-theme/my-first-theme/web/css/source/abc.css
my js path app/design/frontend/custom-theme/my-first-theme/web/js/filename.js
app/design/frontend/custom-theme/my-first-theme/web/js/filename.js