devtools: add experimental section.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

devtools/changelog.py

@@ -17,7 +17,7 @@ sections = [
     'deprecated',
     'fixed',
     'removed',
-    'security',
+    'experimental',
 ]
 
 repo = 'ElementsProject/lightning'
@@ -132,8 +132,8 @@ ${h3} Removed
 ${group(groups['removed']) | trim}
 ${h3} Fixed
 ${group(groups['fixed']) | trim}
-${h3} Security
-${group(groups['security']) | trim}
+${h3} EXPERIMENTAL
+${group(groups['experimental']) | trim}
 
 % for l in links:
 [${l.ref}]: ${l.url}

doc/STYLE.md

@@ -230,8 +230,7 @@ have a line with one of the following prefixes:
    not yet removed
  - `Changelog-Fixed: ` if a bug has been fixed
  - `Changelog-Removed: ` if a (previously deprecated) feature has been removed
- - `Changelog-Security: ` if a security issue has been addressed and the users
-   will need to upgrade in order to stay secure
+ - `Changelog-Experimental: ` if it only affects --enable-experimental-features builds, or experimental- config options.
  
 In case you think the pull request is small enough not to require a changelog
 entry please use `Changelog-None` in one of the commit messages to opt out.