Use math notation in array rules docs (#290)

* Bump required version of Documenter

* Add macros from physics package

* Use Re and Im

* Use tr

* Remove wayward comma

* Number equations correctly

* Engage inline equation syntax

* Use ip

* Remove conj

* Use asterisk for conjugate

* Link to LU rule blog post

As recommended by @nickrobinson251 in JuliaDiff/ChainRules.jl#354 (comment)

* Use inner product everywhere

* Use mathrm

* Use inner product in more places

* Add Sylvester equation example

* Use mathsf for (conjugate) transpose

* Add missing sign

* Clarify language

Author: sethaxen

docs/Project.toml

@@ -6,5 +6,5 @@ DocumenterTools = "35a29f4d-8980-5a13-9543-d66fff28ecb8"
 Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 
 [compat]
-Documenter = "0.25"
+Documenter = "0.25.2"
 DocumenterTools = "0.1.6"

docs/make.jl

@@ -26,7 +26,21 @@ makedocs(
     format=Documenter.HTML(
         prettyurls=false,
         assets=["assets/chainrules.css"],
-        mathengine=MathJax(),
+        mathengine=MathJax3(
+            Dict(
+                :tex => Dict(
+                    "inlineMath" => [["\$","\$"], ["\\(","\\)"]],
+                    "tags" => "ams",
+                    # TODO: remove when using physics package
+                    "macros" => Dict(
+                        "ip" => ["{\\left\\langle #1, #2 \\right\\rangle}", 2],
+                        "Re" => "{\\operatorname{Re}}",
+                        "Im" => "{\\operatorname{Im}}",
+                        "tr" => "{\\operatorname{tr}}",
+                    ),
+                ),
+            ),
+        ),
     ),
     sitename="ChainRules",
     authors="Jarrett Revels and other contributors",