app-admin/doas-sudo-shim: add doc USE flag for man pages

- Add IUSE="doc" to control optional man page generation
- Add BDEPEND on dev-ruby/asciidoctor when USE=doc
- Use conditional emake targets (install-exec, install-man) in src_install
- Remove redundant S assignment (default value)

Signed-off-by: Theron York <theron.york@cloudnuke.org>

app-admin/doas-sudo-shim/doas-sudo-shim-0.2.0.ebuild

@@ -7,15 +7,24 @@ DESCRIPTION="sudo shim that utilizes doas"
 HOMEPAGE="https://github.com/jirutka/doas-sudo-shim"
 SRC_URI="https://github.com/jirutka/doas-sudo-shim/archive/v${PV}.tar.gz -> ${P}.tar.gz"
 
-S="${WORKDIR}/${P}"
 LICENSE="ISC"
 SLOT="0"
 KEYWORDS="~amd64"
+IUSE="doc"
 
+BDEPEND="doc? ( dev-ruby/asciidoctor )"
 RDEPEND="app-admin/doas"
 
+src_compile() {
+	if use doc; then
+		emake man
+	fi
+}
+
 src_install() {
-	dobin sudo
+	local targets="install-exec"
+	use doc && targets+=" install-man"
+	emake DESTDIR="${ED}" PREFIX=/usr ${targets}
 	dodoc README.adoc LICENSE
 }