MD-Note is a simple browser extension for Chrome that allows you to save text selections as markdown or plain text notes. With this extension, you can easily capture important information from any web page and save it for later reference.

To use MD-Note, simply select the text you want to save on any web page. Then, press Alt + S (the shortcut can be modified through chrome://extensions/shortcuts/) to open the MD-Note popup. In the popup, you can edit your note and format it using markdown syntax.

MD-Note also provides some handy shortcuts to add rich text capabilities to your notes. Press Ctrl + B to add ** around the selected text, Ctrl + I to add * around the selected text, Ctrl + ` to add ` around the selected text, and Ctrl + [ to convert the selected text into a link.

Once you have edited your note, press the Save button to show a save file picker. From there, you can select a directory and choose a new file name for your note.

Please note that MD-Note has limited support for copying text from PDF files. It works best for files hosted online and viewed through the default Chrome PDF plugin.