Fix typos in NDifferentiable examples

[ChrisRackauckas]

No description provided.

[codecov]

Codecov Report

Merging #121 into master will increase coverage by 0.34%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #121      +/-   ##
==========================================
+ Coverage   93.96%   94.31%   +0.34%     
==========================================
  Files          10       10              
  Lines         497      510      +13     
==========================================
+ Hits          467      481      +14     
+ Misses         30       29       -1

Impacted Files	Coverage Δ
src/interface.jl	94.4% <0%> (+0.33%)	⬆️
src/objective_types/oncedifferentiable.jl	87.2% <0%> (+0.62%)	⬆️
src/objective_types/constraints.jl	96.52% <0%> (+0.9%)	⬆️
src/NLSolversBase.jl	81.81% <0%> (+1.81%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1defd33...27832f8. Read the comment docs.