add Greek small letters to the technical spelling dictionary

Greek upper case letters have already been ignored during
spell checking, so there is no reason to avoid the small ones,
especially because they are frequently used in scientific and
technical writings.

Change-Id: I128fe8c51b7e9802c18fc282674998741c8e4fb2

extras/source/wordbook/technical.dic

@@ -235,3 +235,28 @@ Xubuntu
 Yahoo
 YouTube
 ZENworks
+α
+β
+γ
+δ
+ε
+ζ
+η
+θ
+ι
+κ
+λ
+μ
+ν
+ξ
+ο
+π
+ρ
+ς
+σ
+τ
+υ
+φ
+χ
+ψ
+ω