Add comments to supplied BLT files

tests/data/ACT2020Kurrajong.blt

@@ -1,3 +1,6 @@
+# Comment: 2020 ACT Legislative Assembly election, Kurrajong electorate - all votes - ACT STV
+# Source: https://www.elections.act.gov.au/elections_and_voting/2020_legislative_assembly_election/ballot-paper-preference-data-2020-election
+# Contributor: RunasSudo
 28 5
 6 1 0
 3 1 2 3 4 0

tests/data/CSM15.blt

@@ -1,3 +1,6 @@
+# Comment: EVE Online election for CSM15 - all votes - Wright STV
+# Source: https://www.eveonline.com/news/view/meet-the-new-council
+# Contributor: RunasSudo
 40 10
 4115 26 40 32 24 17 1 33 12 34 13
 1817 33 30 4 6 2 21 36 24 35 31

tests/data/ers97.blt

@@ -1,3 +1,6 @@
+# Comment: Ballot papers derived from the ERS97 model election - all votes - ERS97
+# Source: RunasSudo <https://yingtongli.me/blog/2021/01/04/ers97.html> based on https://www.electoral-reform.org.uk/latest-news-and-research/publications/how-to-conduct-an-election-by-the-single-transferable-vote-3rd-edition/
+# Contributor: RunasSudo
 11 6
 35 1 2
 3 1 3 9

tests/data/linn07.blt

@@ -1,3 +1,6 @@
+# Comment: Votes cast in the 2007 Scotland local government election, Linn ward - all votes - Scottish STV
+# Source: https://web.archive.org/web/20121004213938/http://www.glasgow.gov.uk/en/YourCouncil/Elections_Voting/Election_Results/ElectionScotland2007/LGWardResults.htm?ward=1&wardname=1%20-%20Linn
+# Contributor: RunasSudo
 11 4
 295 1 0
 2 1 11 0

tests/data/meekm.blt

@@ -1,3 +1,6 @@
+# Comment: Sample BLT file from Algorithm 123 specification - Meek STV
+# Source: Hill ID, Wichmann BA, Woodall DR <https://www.dia.govt.nz/diawebsite.NSF/Files/meekm/%24file/meekm.pdf>
+# Contributor: RunasSudo
 4 2
 -2
 3 1 3 4 0

tests/data/prsa1.blt

@@ -1,3 +1,6 @@
+# Comment: Sample ballot papers for Example 1 in the PRSA manual - PRSA 1977
+# Source: https://www.prsa.org.au/type_3fo.xls
+# Contributor: RunasSudo
 7 4
 1 1 3 0
 1 2 4 7 0