Fix link in tutorial

[codecov[bot]]

Codecov Report

Base: 97.32% // Head: 97.42% // Increases project coverage by +0.09% :tada:

Coverage data is based on head (f9bb1cf) compared to base (9591943). Patch has no changes to coverable lines.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #270 +/- ## ========================================== + Coverage 97.32% 97.42% +0.09% ========================================== Files 14 14 Lines 1009 1009 ========================================== + Hits 982 983 +1 + Misses 27 26 -1 ``` | [Impacted Files](https://codecov.io/gh/JuliaSmoothOptimizers/LinearOperators.jl/pull/270?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers) | Coverage Δ | | |---|---|---| | [src/utilities.jl](https://codecov.io/gh/JuliaSmoothOptimizers/LinearOperators.jl/pull/270?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers#diff-c3JjL3V0aWxpdGllcy5qbA==) | `96.47% <0.00%> (+1.17%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaSmoothOptimizers)

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Package name	latest	stable
CaNNOLeS.jl
DCISolver.jl
FletcherPenaltySolver.jl
JSOSolvers.jl
Krylov.jl
NLPModels.jl
NLPModelsModifiers.jl
PROPACK.jl
Percival.jl
QuadraticModels.jl
SolverTools.jl