I feel like this must be a really dumb question but I've yet to find an answer.
I am having trouble with some files ending with .txt and .md not showing in the file list of my projects (left pane within Atom, on MacOS). The readme.txt in lib shows up as do the README.md and LICENSE.md files. However I have added a few other files (tried both .txt and .md) and they will show up very briefly in the list and then disappear. An example would be a file named Notes.txt. The files are within the project folder on disk, they just don't show up in the list in PlatformIO's project tab.
Some .txt files that fail to show I copied in, I have also created some using the Add File in PlatformIO and both paths lead to the files not showing up.