chore(readme): Updating readme with PyCharm code completion info (#246)

Author: m-strzelczyk

packages/google-cloud-compute/README.rst

@@ -68,6 +68,15 @@ Windows
     <your-env>\Scripts\activate
     <your-env>\Scripts\pip.exe install google-cloud-compute
 
+
+PyCharm/JetBrains IDEs
+~~~~~~~~~~~~~~~~~~~~~~
+Since the library has grown in size, the files it consists of have outgrown the [default size limit of ~2.5Mb](https://www.jetbrains.com/help/pycharm/file-idea-properties.html).
+As a result, the code completion in JetBrains products can fail to work with the classes from our library. To
+fix this, you need to update the `idea.max.intellisense.filesize` setting in custom properties
+(Help -> Edit custom properties...). Just add a line like `idea.max.intellisense.filesize = 10000` to change this
+limit to ~10Mb.
+
 Next Steps
 ~~~~~~~~~~