fix typos in docs (#3384)

Author: spaette

src/abstractdataframe/abstractdataframe.jl

@@ -254,7 +254,7 @@ function rename!(df::AbstractDataFrame,
     return df
 end
 
- # needed because of dispach ambiguity
+ # needed because of dispatch ambiguity
 function rename!(df::AbstractDataFrame)
     _drop_all_nonnote_metadata!(parent(df))
     return df

test/select.jl

@@ -2853,7 +2853,7 @@ end
                   DataFrame(x=[missing, missing, missing])
             @test combine(table, AsTable([p, q]) => ByRow(median∘skipmissing) => :x) ==
                   DataFrame(x=[1, 2, 4])
-            # a bit surpriting how non-broadcasted and broadcasted minimum works
+            # a bit surprising how non-broadcasted and broadcasted minimum works
             @test combine(table, AsTable([p, q]) => minimum => :x) ==
                   DataFrame(x=[1, 2, 4])
             @test combine(table, AsTable([p, q]) => ByRow(minimum) => :x) ≅