How to install locally
If you want to modify TrelloExport, for example to submit a PR, you have to clone the repository or download the zip from the Releases page at GitHub, and then install it locally.
In order to do that you have to disable the extension from the store, download the zip or clone the repository and install into your browser.
If you download the zip, extract/unzip the code in a folder of your choice. If you clone the repo, it will be in the directory you specify when cloning.
Then in Chrome go to Menu (the three lines)->More tools->Extensions. Click the “Developer mode” checkbox and then click “Load unpacked extension…”. Finally select the folder where you unzipped the downloaded file or cloned the repo.
The extension will now run just like when you install it from the store.