Added

• Add f'{format}' strings (#2985 by casey)
• Use double braces {{…}} for format strings (#2993 by casey)
• Stabilize [script] attribute (#2988 by casey)

Changed

• Allow newlines in interpolations and } to abut interpolation }} (#2992 by casey)

Misc

• Test format strings with conditionals (#2991 by casey)
• Move StringState into module (#2989 by casey)
• Test undefined variable in format string error (#2987 by casey)
• Update softprops/action-gh-release to 2.5.0 (#2979 by app/dependabot)
• Link to just-lsp in readme (#2846 by terror)