feat: number of feats and fixes signal

[huang-benny]

This PR adds a new 'numberOfFeatsAndFixes' signal to the MAINTENANCE pillar that counts the number of features and bug fixes mentioned in release notes from the past year.

Changes:

• Fetches release data from GitHub GraphQL API (already available in existing queries)
• Uses releases query to get release descriptions from the past year
• Added countFeatsAndFixes() function in src/lib/utils/releaseNotes.ts to count occurrences
• Counts all occurrences of "feat" and "fix" keywords (case-insensitive) in release descriptions
• Returns 0 if release data is unavailable or no releases exist

Scoring:

• ≥28 features/fixes: 5 stars
• 10-27 features/fixes: 4 stars
• 2-9 features/fixes: 3 stars
• 1 feature/fix: 2 stars
• 0 features/fixes: 1 star

Example CLI Input and Output:

./bin/cdk-construct-analyzer cdk-ecr-deployment --details    

LIBRARY: cdk-ecr-deployment
VERSION: 4.0.3

OVERALL SCORE: 76/100

---

SUBSCORES
  MAINTENANCE :           67/100
  QUALITY     :           80/100
  POPULARITY  :           88/100

---

=== MAINTENANCE ===                                   SCORE  WEIGHT
— Time To First Response ............................ ★★☆☆☆    15
— Provenance Verification ........................... ★★★★★    10
— Release Frequency ................................. ★★★★☆    10
— Number Of Contributors - Maintenance .............. ★★★★☆    5
— Number Of Feats And Fixes ......................... ★★★★★    5

=== QUALITY ===                                       SCORE  WEIGHT
— Documentation Completeness ........................ ★★★★☆    5
— Tests Checklist ................................... ★★★☆☆    5
— Author Package Count .............................. ★★★★★    5
— Release Notes Include Feats And Fixes ............. ★★★★★    5
— Stable Versioning ................................. ★★★★☆    5

=== POPULARITY ===                                    SCORE  WEIGHT
— Weekly Downloads .................................. ★★★★★    15
— Github Stars ...................................... ★★★★☆    10
— Number Of Contributors - Popularity ............... ★★★★☆    5

[huang-benny]

The README was not fully updated in the multi language signal PR, so I updated it in this PR by adding the description of the signal on line 164