Add many "see also" links to docstrings

base/irrationals.jl

@@ -19,7 +19,7 @@ for integers `n` will give a rational result when `n` is a perfect square), then
 abstract type AbstractIrrational <: Real end
 
 """
-    Irrational{sym} <: AbstractIrrational
+`Irrational{sym}` <: [`AbstractIrrational`](@ref)
 
 Number type representing an exact irrational value denoted by the
 symbol `sym`, such as [`π`](@ref pi), [`ℯ`](@ref) and [`γ`](@ref Base.MathConstants.eulergamma).

base/special/exp.jl

@@ -264,12 +264,17 @@ end
 @doc """
     exp(x)
 
-Compute the natural base exponential of `x`, in other words ``e^x``.
+Compute the natural base exponential of `x`, in other words ``ℯ^x``.
+
+See also [`exp2`](@ref), [`exp10`](@ref) and [`cis`](@ref).
 
 # Examples
 ```jldoctest
 julia> exp(1.0)
 2.718281828459045
+
+julia> exp(im * pi) == cis(pi)
+true
 ```
 """ exp(x::Real)
 
@@ -279,10 +284,18 @@ julia> exp(1.0)
 
 Compute the base 2 exponential of `x`, in other words ``2^x``.
 
+See also [`ldexp`](@ref), [`<<`](@ref).
+
 # Examples
 ```jldoctest
 julia> exp2(5)
 32.0
+
+julia> 2^5
+32
+
+julia> exp2(63) > typemax(Int)
+true
 ```
 """
 exp2(x)
@@ -296,6 +309,9 @@ Compute the base 10 exponential of `x`, in other words ``10^x``.
 ```jldoctest
 julia> exp10(2)
 100.0
+
+julia> 10^2
+100
 ```
 """
 exp10(x)

base/strings/io.jl

@@ -57,9 +57,6 @@ end
 Print (using [`print`](@ref)) `xs` followed by a newline.
 If `io` is not supplied, prints to [`stdout`](@ref).
 
-See also [`@show`](@ref) to print variables names with values,
-and [`Printf.@printf`](@ref man-printf) to format numbers.
-
 # Examples
 ```jldoctest
 julia> println("Hello, world")