Reduce manual to a single page, enable doc previews (#140)

Having two pages were one is just a TOC seems pointless

docs/make.jl

@@ -6,10 +6,10 @@ makedocs(
 	sitename = "OrderedCollections.jl",
     pages = [
         "index.md",
-        "ordered_containers.md",
     ]
 )
 
 deploydocs(
-    repo = "github.com/JuliaCollections/OrderedCollections.jl.git"
+    repo = "github.com/JuliaCollections/OrderedCollections.jl.git",
+    push_preview = true,
 )

docs/src/index.md

@@ -6,11 +6,77 @@ This package implements associative containers that preserve the order of insert
 -   OrderedSet
 -   LittleDict
 
-## Contents
 
-```@contents
-Pages = [
-    "index.md",
-    "ordered_containers.md",
-]
+## OrderedSets
+
+`OrderedSets` are sets whose entries have a particular order.
+Order refers to *insertion order*, which allows deterministic
+iteration over the set:
+
+```julia
+using Base.MathConstants
+s = OrderedSet((π,e,γ,catalan,φ))
+for x in s
+   println(x)
+end
+#> π = 3.1415926535897...
+#> ℯ = 2.7182818284590...
+#> γ = 0.5772156649015...
+#> catalan = 0.9159655941772...
+#> φ = 1.6180339887498...
+```
+All `Set` operations are available for OrderedSets.
+
+Note that to create an OrderedSet of a particular type, you must
+specify the type in curly-braces:
+
+```julia
+# create an OrderedSet of Strings
+strs = OrderedSet{AbstractString}()
+```
+
+## OrderedDicts
+Similarly, `OrderedDict` are simply dictionaries whose entries have a particular
+order.
+```julia
+d = OrderedDict{Char,Int}()
+for c in 'a':'d'
+    d[c] = c-'a'+1
+end
+for x in d
+   println(x)
+end
+#> 'a' => 1
+#> 'b' => 2
+#> 'c' => 3
+#> 'd' => 4
+```
+The insertion order is conserved when iterating on the dictionary itself,
+its keys (through `keys(d)`), or its values (through `values(d)`).
+All standard `Associative` and `Dict` functions are available for `OrderedDicts`
+
+## LittleDict
+```julia
+d = LittleDict{Char,Int}()
+for c in 'a':'d'
+    d[c] = c-'a'+1
+end
+for x in d
+   println(x)
+end
+#> 'a' => 1
+#> 'b' => 2
+#> 'c' => 3
+#> 'd' => 4
+```
+The `LittleDict` acts similarly to the `OrderedDict`.
+However for small collections it is much faster.
+Indeed the preceeding example (with the io redirected to `devnull`), runs 4x faster in the `LittleDict` version as the earlier `OrderedDict` version.
+
+```@docs
+OrderedDict
+OrderedSet
+LittleDict
+freeze
+OrderedCollections.isordered
 ```