Display Documenter version in document build info.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Documenter.jl changelog
 
+## Version `v0.27.3`
+
+* ![Enhancement][badge-enhancement] The version of Documenter used for generating a document is now displayed in the build information. ([#1602][github-1602])
+
 ## Version `v0.27.2`
 
 * ![Enhancement][badge-enhancement] The default font has been changed to `Lato Medium` so that the look of the text would be closer to the old Google Fonts version of Lato. ([#1602][github-1602], [#1604][github-1604])

src/Writers/HTMLWriter.jl

@@ -796,6 +796,13 @@ function render_html(ctx, navnode, head, sidebar, navbar, article, footer, scrip
     )
 end
 
+function documenter_version()
+    project = joinpath(dirname(dirname(pathof(Documenter))), "Project.toml")
+    toml = read(project, String)
+    m = match(r"^version\s*=\s\"(.*)\"$"m, toml)
+    return VersionNumber(m[1])
+end
+
 """
 Renders the modal settings dialog.
 """
@@ -813,6 +820,7 @@ function render_settings(ctx)
     buildinfo = p(
         "This document was generated with ",
         a[:href => "https://github.com/JuliaDocs/Documenter.jl"]("Documenter.jl"),
+        " version $(documenter_version())",
         " on ",
         span[".colophon-date", :title => now_full](now_short),
         ". ",