Make installing from the git archive of a tagged commit possible

aka make GitHub release assets usable.

Requires setuptools-scm-git-archive.

.git_archival.txt

@@ -0,0 +1 @@
+ref-names: $Format:%D$

.gitattributes

@@ -1,3 +1,4 @@
+.git_archival.txt export-subst
 .gitattributes export-ignore  
 .gitignore export-ignore
 /doc/web export-ignore

doc/development.md

@@ -74,4 +74,4 @@ Release process
 
 8. check distribution files (`twine check dist/*`) and upload to PyPI (`twine upload dist/*`)
 
-9. create release (vX.Y.Z) on GitHub (warn users about GitHub archives)
+9. create release (vX.Y.Z) on GitHub

doc/install.txt

@@ -7,6 +7,10 @@ When installing from source, for application translations to be installed
 polib_ needs to be installed before LinkChecker. After LinkChecker installation
 polib_ can be removed.
 
+Installing from the GitHub release assets requires setuptools-scm-git-archive_.
+
+pip-run_ may be useful for both of these cases.
+
 There are several steps to resolve problems with detecting the character
 encoding of checked HTML pages:
 first ensure the web server, if used, is not returning an incorrect charset in
@@ -20,10 +24,14 @@ used.
 
 .. _chardet: https://pypi.org/project/chardet/
 
+.. _pip-run: https://pypi.org/project/pip-run/
+
 .. _cchardet: https://pypi.org/project/cchardet/
 
 .. _polib: https://pypi.org/project/polib/
 
+.. _setuptools-scm-git-archive: https://pypi.org/project/setuptools-scm-git-archive/
+
 .. _venv: https://docs.python.org/3/library/venv.html#creating-virtual-environments
 
 Setup with pip