When I generate sprite sheet from a symbol that consists of 16 individual images how do I get the published HTML file to read that sprite sheet instead of publishing out all individual images.
I don't understand the question. If you want your Canvas project to use sprite sheets instead of individual image assets, you just go to the publish settings and set Export as: Spritesheet.
To give a different kind of answer, the export symbol to spritesheet is more used for creating spritesheets for other tools to use. If you're exporting to HTML5 Canvas you would let the publishing settings create the spritesheet or texture map.