Feat: Added automatic determination of task number based on complexity (#884)

- Added 'defaultNumTasks: 10' to default config, now used in 'parse-prd'
- Adjusted 'parse-prd' and 'expand-task' to:
  - Accept a 'numTasks' value of 0
  - Updated tool and command descriptions
  - Updated prompts to 'an appropriate number of' when value is 0
- Updated 'README-task-master.md' and 'command-reference.md' docs
- Added more tests for: 'parse-prd', 'expand-task' and 'config-manager'

Co-authored-by: Ralph Khreish <35776126+Crunchyman-ralph@users.noreply.github.com>

docs/configuration.md

@@ -36,6 +36,7 @@ Taskmaster uses two primary methods for configuration:
         "global": {
           "logLevel": "info",
           "debug": false,
+          "defaultNumTasks": 10,
           "defaultSubtasks": 5,
           "defaultPriority": "medium",
           "defaultTag": "master",