Convert line endings from CRLF to LF

[trxcllnt]

Fix an issue where git shows modifications immediately after cloning in Linux.

According to this, anybody committing from Windows should either:

• configure their editor to use LF and set git config --global core.autocrlf false
• keep using CRLF in editors, and set git config --global core.autocrlf true

[leofang]

/ok to test

[leofang]

cc @ksimpson-work

Thanks, Paul! Confirmed locally that this is the only actual change

$ git diff main  -w
diff --git a/.gitattributes b/.gitattributes
index 00407cd..aeb3200 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -5,3 +5,5 @@ cuda/_version.py export-subst
 # we do not own any headers checked in, don't touch them
 *.h binary
 *.hpp binary
+# git should not convert line endings in PNG files
+*.png binary

[leofang]

anybody committing from Windows should either:

yes, xref: #201 (review)