Add more ohm prefixes

Author: MilesCranmer

src/units.jl

@@ -108,8 +108,8 @@ end
 @add_prefixes C ()
 @add_prefixes V (p, n, μ, u, m, k, M, G)
 @add_prefixes F ()
-@add_prefixes Ω (m,)
-@add_prefixes ohm (m,)
+@add_prefixes Ω (n, μ, u, m)
+@add_prefixes ohm (n, μ, u, m)
 @add_prefixes T ()
 
 # SI derived units
@@ -146,7 +146,7 @@ end
     F,
 )
 @doc(
-    "Resistance in Ohms. Available variant: `mΩ`. Also available is ASCII `ohm` (with variant `mohm`).",
+    "Resistance in Ohms. Available variant: `nΩ`, `μΩ` (/`uΩ`), `mΩ`. Also available is ASCII `ohm` (with variants `nohm`, `μohm` (/`uohm`), `mohm`).",
     Ω,
 )
 @doc(