Update src/weights.jl

Co-Authored-By: Milan Bouchet-Valat <nalimilan@club.fr>

src/weights.jl

@@ -211,7 +211,7 @@ For each element `i` in `t` the weight value is computed as:
 
 - `t::AbstractVector`: temporal indices or timestamps
 - `r::StepRange`: a larger range to use when constructing weights from a subset of timestamps
-- `n::Integer`: number of temporal indices to assume for the exponential weighting
+- `n::Integer`: if provided instead of `t`, temporal indices are taken to be `1:n`
 - `λ::Real`: a smoothing factor or rate parameter such that ``0 < λ ≤ 1``.
   As this value approaches 0, the resulting weights will be almost equal,
   while values closer to 1 will put greater weight on the tail elements of the vector.