Fix indentation of doc strings

[joschmitt]

The function name in a doc strings must be indented by 4 spaces to be printed correctly in the REPL.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.31%. Comparing base (f9e5c0f) to head (3402dd9).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3744      +/-   ##
==========================================
- Coverage   81.32%   81.31%   -0.01%     
==========================================
  Files         579      579              
  Lines       78982    78982              
==========================================
- Hits        64229    64228       -1     
- Misses      14753    14754       +1     

Files	Coverage Δ
experimental/LieAlgebras/src/LieSubalgebra.jl	66.97% <ø> (ø)
experimental/LieAlgebras/src/RootSystem.jl	62.42% <ø> (ø)
...ntal/QuadFormAndIsom/src/lattices_with_isometry.jl	99.44% <ø> (ø)
experimental/Schemes/src/Sheaves.jl	64.70% <ø> (ø)
experimental/Schemes/src/SpaceGerms.jl	69.91% <ø> (ø)
experimental/Schemes/src/elliptic_surface.jl	4.47% <ø> (ø)
...c/AlgebraicGeometry/Curves/ProjectivePlaneCurve.jl	91.35% <ø> (ø)
...ometry/Schemes/AffineSchemes/Objects/Attributes.jl	89.88% <ø> (ø)
...ometry/Schemes/AffineSchemes/Objects/Properties.jl	90.45% <ø> (ø)
...metry/Schemes/CoveredSchemes/Objects/Properties.jl	78.04% <ø> (ø)
... and 12 more

... and 1 file with indirect coverage changes

[lkastner]

Thank you.

[joschmitt]

Two approvals, so merge please. I am not allowed to.