LF is standard line ending (convert few CRLF files)

There were three files with the wrong line endings, they're now
converted. Added .gitattributes and .editorconfig to make this clear and
documented.

Author: holybiber

.editorconfig

@@ -0,0 +1,18 @@
+# https://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.py]
+indent_style = space
+indent_size = 4
+
+[Makefile]
+indent_style = tab
+
+[*.md]
+trim_trailing_whitespace = false

.gitattributes

@@ -0,0 +1,13 @@
+# Normalize text files to LF in the repository and on checkout (all platforms).
+* text=auto eol=lf
+
+# Binary assets (do not line-ending-normalize)
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.webp binary
+*.pdf binary
+*.odt binary
+*.odg binary
+*.lwp binary