Add pelican support (#744)

* add support for deploy attribute

* improved `to_deploy` logic

* test deploy/deploy-dir logic

* revert elaborate example, create project to test deploy stuff programmatically

* add pelican and rough draft theme

* update pelican template, add example files

* formatting

* move pelican theme files

* wip

* format

* sample source

* halfway working pelican_default

* lint

* formatting

* ignore Pelican type errors

* 3.8 compatible typing

* install pelican

* add styling and background to pelican theme

* bump copyright

* fix styling

* update stage_deployment

* update pelican-theme

* format

Author: StevenClontz

pelican-testing.py

@@ -0,0 +1,30 @@
+from pelican import Pelican
+from pelican.settings import configure_settings, DEFAULT_CONFIG
+from pretext.project import Project
+
+config = DEFAULT_CONFIG
+config["PATH"] = "foobar-in"
+config["THEME"] = "pelican-ptx"
+config["OUTPUT_PATH"] = "foobar-out"
+config["RELATIVE_URLS"] = True
+config["TIMEZONE"] = "Etc/UTC"
+config["ARTICLE_PATHS"] = ["updates"]
+config["ARTICLE_SAVE_AS"] = "updates/{date:%Y%m%d}-{slug}.html"
+config["ARTICLE_URL"] = config["ARTICLE_SAVE_AS"]
+
+p = Project.parse("new-pretext-project")
+root = p.get_target().source_element()
+for title_ele in root.iterdescendants("title"):
+    config["SITENAME"] = title_ele.text
+    break
+else:
+    config["SITENAME"] = "My PreTeXt Project"
+for title_ele in root.iterdescendants("subtitle"):
+    config["SITESUBTITLE"] = title_ele.text
+    break
+
+config["PTX_TARGETS"] = [
+    (t.name.capitalize(), t.deploy_dir_path()) for t in p.deploy_targets()
+]
+
+Pelican(configure_settings(config)).run()