adds missing dimension md file

Author: ederc

docs/src/dimension.md

@@ -0,0 +1,31 @@
+```@meta
+CurrentModule = AlgebraicSolving
+DocTestSetup = quote
+  using AlgebraicSolving
+end
+```
+
+```@setup algebraicsolving
+using AlgebraicSolving
+```
+
+```@contents
+Pages = ["dimension.md"]
+```
+
+# Krull dimension of an ideal
+
+## Introduction
+
+AlgebraicSolving allows to compute the Krull dimension for the ideal spanned
+by given input generators over finite fields of characteristic smaller
+$2^{31}$ and over the rationals.
+
+The underlying engine is provided by msolve.
+
+## Functionality
+
+```@docs
+    dimension(I::Ideal{T}) where T <: MPolyRingElem
+```
+