doc: changelogs: rename to CHANGES.md

These have been an adhoc mixture of plain text, markdown and org, and
used in each mode at different times. They will now have a definite
format, which for now is markdown. Org was another contender.

[ci skip]

hledger-api/package.yaml

@@ -22,7 +22,7 @@ stability: alpha
 tested-with: GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 
 extra-source-files:
-- CHANGES
+- CHANGES.md
 - README
 - examples/*.html
 - hledger-api.1

hledger-lib/package.yaml

@@ -21,7 +21,7 @@ stability: stable
 tested-with: GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 
 extra-source-files:
-- CHANGES
+- CHANGES.md
 - README
 - hledger_csv.5
 - hledger_csv.txt

hledger-ui/package.yaml

@@ -23,7 +23,7 @@ stability   : stable
 tested-with : GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 
 extra-source-files:
-  - CHANGES
+  - CHANGES.md
   - README
   - hledger-ui.1
   - hledger-ui.txt

hledger-web/package.yaml

@@ -23,7 +23,7 @@ stability: stable
 tested-with: GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 
 extra-source-files:
-- CHANGES
+- CHANGES.md
 - README
 - config/favicon.ico
 - config/keter.yaml

hledger/package.yaml

@@ -23,7 +23,7 @@ stability: stable
 tested-with: GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 
 extra-source-files:
-- CHANGES
+- CHANGES.md
 - README.md
 - test/test.hs
 - bench/10000x1000x10.journal