Betty 0.3.0b7

What's Changed

• Prevent the Demo server from stopping early by @bartfeenstra in #1144
• Render documentation using Sphinx by @bartfeenstra in #1143
• Add a favicon to the documentation by @bartfeenstra in #1150
• Update all links to Twitter by @bartfeenstra in #1152
• Remove an empty and redundant documentation page by @bartfeenstra in #1151
• Remove the Previous and Next buttons from the documentation by @bartfeenstra in #1153
• Fix a typo by @bartfeenstra in #1154
• Link to extension classes from their documentation pages by @bartfeenstra in #1155
• Link to the documentation from the README by @bartfeenstra in #1156
• Remove the PyInstaller build for Linux by @bartfeenstra in #1157
• Document that extensions are configurable through Betty Desktop as well by @bartfeenstra in #1158
• Fix incorrect example configuration by @bartfeenstra in #1159

Full Changelog: 0.3.0b6...0.3.0b7