Update documentation dependencies

Author: kdheepak

docs/make.jl

@@ -11,8 +11,10 @@ deploydocs(
     repo = "github.com/kdheepak/TerminalUserInterfaces.jl.git",
     deps = Deps.pip(
                    "mkdocs",
+                   "mkdocs-material",
                    "python-markdown-math",
                    "pygments",
+                   "pymdown-extensions",
                    ),
     make = () -> run(`mkdocs build`),
     target = "site",