Docs: fix grammar and explicit B1 config

Fix grammar in Rule 3 description and explicitly
configure body-max-line-length to 72 in .gitlint
so documentation accurately reflects configured
values rather than implicit defaults.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Andrew Grimberg <tykeal@bardicgrove.org>

.gitlint

@@ -45,9 +45,8 @@ line-length=50
 # (e.g. title-must-not-contain-word).
 # regex=^US[0-9]*
 
-# [B1]
-# B1 = body-max-line-length
-# line-length=120
+[body-max-line-length]
+line-length=72
 
 # [body-min-length]
 # min-length=5

AGENTS.md

@@ -38,7 +38,7 @@ Keep subjects concise. The hard limit is 50 characters.
 ### Rule 3: Capitalize the subject line
 
 The subject line MUST start with a capital letter. This project uses
-Conventional Commits with capitalized types which naturally satisfies this rule.
+Conventional Commits, whose capitalized types naturally satisfy this rule.
 
 - **Enforcement**: gitlint `contrib-title-conventional-commits` requires
   capitalized types.
@@ -76,7 +76,7 @@ Bad examples:
 Body text MUST be wrapped at 72 characters per line. Lines containing URLs
 MAY exceed this limit, but enforcement tooling has limitations.
 
-- **Enforcement**: gitlint `body-max-line-length` (default 72). The
+- **Enforcement**: gitlint `body-max-line-length` (configured to 72). The
   configured `ignore-by-body` rule disables this check for the entire
   commit body if any line matches the URL pattern, so you MUST still
   manually wrap non-URL lines to 72 characters.