Update README.md (#1203)

* Update README.md

added #153 to readme for awareness

* Update README.md

---------

Co-authored-by: Andrew Lisowski <lisowski54@gmail.com>

README.md

@@ -27,6 +27,10 @@
 >
 > As of v0.10.4, core-js is no longer included with jimp or its extensions. If you rely on core-js, install it with either `yarn add core-js` or `npm i core-js`
 
+> ## Read before installing
+>
+> Please be aware that Jimp is built on JavaScript implementations of image formats so in some cases that might [allocate a lot of memory](https://github.com/jimp-dev/jimp/issues/153) before using.
+
 ## Installation
 
 Installation: `npm install --save jimp`