v0.3.9

What's Changed

• Add JOSS badge by @naik-aakash in #248
• Add note about dummy potcar to example file by @naik-aakash in #249
• Fix link to changelog by @naik-aakash in #250
• Fix citation and readme by @JaGeo in #251
• remove redundant orbplot arg and fix a typo by @naik-aakash in #253

Full Changelog: v0.3.8...v0.3.9