Add Spectacle Codemirror extension (FormidableLabs#696)

Author: jonathan-fielding

README.md

@@ -1049,6 +1049,7 @@ The `Typeface` tag is used to apply a specific font to text content. It can eith
 - [Spectacle Code Slide](https://github.com/thejameskyle/spectacle-code-slide) - Step through lines of code using this awesome slide extension by @thejameskyle
 - [Spectacle Terminal Slide](https://github.com/elijahmanor/spectacle-terminal) - Terminal component that can be used in a spectacle slide deck by @elijahmanor
 - [Spectacle Image Slide](https://github.com/FezVrasta/spectacle-image-slide) - Show a slide with a big image and a title on top
+- [Spectacle Codemirror](https://github.com/jonathan-fielding/spectacle) - Show a live code editor inside your slides
 
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