fix(grafana): update dashboard descriptions to list all supported data sources (#8741)

Several dashboard introduction panels hardcoded "GitHub and Jira" as
required data sources, even though the underlying queries use generic
domain layer tables that work with any supported Git tool or issue
tracker. Updated to list all supported sources following the pattern
already used by DORA and WorkLogs dashboards.

Closes #8740

Co-authored-by: Spiff Azeta <spiffazeta@gmail.com>

Author: spiffaz

grafana/dashboards/EngineeringOverview.json

@@ -40,7 +40,7 @@
           "showLineNumbers": false,
           "showMiniMap": false
         },
-        "content": "- Use Cases: This dashboard is to overview the Git and project management metrics.\n- Data Source Required: Jira + GitHub, or Jira + GitLab.",
+        "content": "- Use Cases: This dashboard is to overview the Git and project management metrics.\n- Data Sources Required:\n   - One of the Git tools, e.g. [GitHub](https://devlake.apache.org/docs/Configuration/GitHub), [GitLab](https://devlake.apache.org/docs/Configuration/GitLab), [Bitbucket](https://devlake.apache.org/docs/Configuration/BitBucket) or [Azure DevOps](https://devlake.apache.org/docs/Configuration/AzureDevOps)\n   - One of the issue tracking tools, e.g. [Jira](https://devlake.apache.org/docs/Configuration/Jira)",
         "mode": "markdown"
       },
       "pluginVersion": "11.0.0",

grafana/dashboards/EngineeringThroughputAndCycleTime.json

@@ -39,7 +39,7 @@
           "showLineNumbers": false,
           "showMiniMap": false
         },
-        "content": "- Use Cases: This dashboard shows the engineering throughput and and cycle time, which helps to identify productivity and bottlenecks of the development process.\n- Data Source Required: GitHub and Jira([transformation](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) required to tell DevLake what the story_points field is)",
+        "content": "- Use Cases: This dashboard shows the engineering throughput and and cycle time, which helps to identify productivity and bottlenecks of the development process.\n- Data Sources Required:\n   - One of the Git tools, e.g. [GitHub](https://devlake.apache.org/docs/Configuration/GitHub), [GitLab](https://devlake.apache.org/docs/Configuration/GitLab), [Bitbucket](https://devlake.apache.org/docs/Configuration/BitBucket) or [Azure DevOps](https://devlake.apache.org/docs/Configuration/AzureDevOps)\n   - One of the issue tracking tools, e.g. [Jira](https://devlake.apache.org/docs/Configuration/Jira) ([Scope Config](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) required to tell DevLake what the story_points field is)",
         "mode": "markdown"
       },
       "pluginVersion": "11.0.0",

grafana/dashboards/EngineeringThroughputAndCycleTimeTeamView.json

@@ -40,7 +40,7 @@
           "showLineNumbers": false,
           "showMiniMap": false
         },
-        "content": "- Use Cases: This dashboard shows the engineering throughput and and cycle time, which helps to identify productivity and bottlenecks of the development process.\n- Data Source Required: GitHub and Jira([transformation](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) required to tell DevLake what the story_points field is). You also need to do [team configuration](https://devlake.apache.org/docs/Configuration/TeamConfiguration) to use this dashboard.",
+        "content": "- Use Cases: This dashboard shows the engineering throughput and and cycle time, which helps to identify productivity and bottlenecks of the development process.\n- Data Sources Required:\n   - One of the Git tools, e.g. [GitHub](https://devlake.apache.org/docs/Configuration/GitHub), [GitLab](https://devlake.apache.org/docs/Configuration/GitLab), [Bitbucket](https://devlake.apache.org/docs/Configuration/BitBucket) or [Azure DevOps](https://devlake.apache.org/docs/Configuration/AzureDevOps)\n   - One of the issue tracking tools, e.g. [Jira](https://devlake.apache.org/docs/Configuration/Jira) ([Scope Config](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) required to tell DevLake what the story_points field is)\n- You also need to do [team configuration](https://devlake.apache.org/docs/Configuration/TeamConfiguration) to use this dashboard.",
         "mode": "markdown"
       },
       "pluginVersion": "11.0.0",

grafana/dashboards/WeeklyBugRetro.json

@@ -40,7 +40,7 @@
           "showLineNumbers": false,
           "showMiniMap": false
         },
-        "content": "- Use Cases: This dashboard can be used to track bugs with metrics such as [Bug Age](https://devlake.apache.org/docs/Metrics/BugAge).\n- Data Source Required: GitHub ([Scope Config](https://devlake.apache.org/docs/UserManuals/ConfigUI/GitHub#step-3---adding-transformation-rules-optional) required) or Jira ([Scope Config](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) required). Scope config is the settings to define which issues are bugs.",
+        "content": "- Use Cases: This dashboard can be used to track bugs with metrics such as [Bug Age](https://devlake.apache.org/docs/Metrics/BugAge).\n- Data Source Required: One of the issue tracking tools, e.g. [GitHub](https://devlake.apache.org/docs/UserManuals/ConfigUI/GitHub#step-3---adding-transformation-rules-optional), [GitLab](https://devlake.apache.org/docs/Configuration/GitLab) or [Jira](https://devlake.apache.org/docs/UserManuals/ConfigUI/Jira#step-3---adding-transformation-rules-optional) (Scope Config required to define which issues are bugs).",
         "mode": "markdown"
       },
       "pluginVersion": "11.0.0",