Fixed a few typos (#502)

Author: pitmonticone

docs/src/chainrules.md

@@ -1,11 +1,11 @@
 ## ChainRulesCore Integration
 
-The `WeightedIndex` infrastructure has issues working with autodiff libraries. Autodiff is facilitate by integration with ChainRulesCore. A custom [rrule](https://juliadiff.org/ChainRulesCore.jl/dev/index.html) is definied such that
+The `WeightedIndex` infrastructure has issues working with autodiff libraries. Autodiff is facilitate by integration with ChainRulesCore. A custom [rrule](https://juliadiff.org/ChainRulesCore.jl/dev/index.html) is defined such that
 
 ```julia
 y, itp_pullback = rrule(itp, 1)
 ```
-`itp_pullback` takes a purturbation on `y` and returns how it effects each `x` dimension. Since `Interpolations` already has a `gradient` function, `pullback` reuses it by scaling it by `Δy`.
+`itp_pullback` takes a perturbation on `y` and returns how it effects each `x` dimension. Since `Interpolations` already has a `gradient` function, `pullback` reuses it by scaling it by `Δy`.
 
 This enables integration with autodiff libraries like Zygote, enabling
 

src/hermite/cubic.jl

@@ -25,7 +25,7 @@ struct CubicHermite
         if (length(xs) != length(ys) || length(ys) != length(dydxs))
             throw(
                 DomainError(
-                    "There must be exactly the same number of abscissasas ordinates and derivatives.",
+                    "There must be exactly the same number of abscissas as ordinates and derivatives.",
                 ),
             )
         end

src/requires/README.md

@@ -1,4 +1,4 @@
 This directory contains files that facilitate the composition of Interpolations.jl with other julia packages.
 
-To add extra code that is loaded using Requries.jl create a new file named after the package of interest and then
+To add extra code that is loaded using Requires.jl create a new file named after the package of interest and then
 modify `__init__` in Interpolations.jl with a `@require` statement to include the file.