docs: document --sqlconfig YAML-only format requirement

Author: dlevy-msft-sql

README.md

@@ -84,6 +84,17 @@ sqlcmd config connection-strings
 sqlcmd config view
 ```
 
+#### Custom Configuration Files
+
+The `--sqlconfig` flag specifies a custom configuration file. Files must be **YAML format** with a `.yaml` or `.yml` extension:
+
+```
+sqlcmd config --sqlconfig ./myproject.yaml add-endpoint --name ep1434 --address localhost --port 1434
+sqlcmd config --sqlconfig ./myproject.yaml view
+```
+
+The default file (`~/.sqlcmd/sqlconfig`) has no extension but is also YAML.
+
 ### Versions
 
 To see all version tags to choose from (2017, 2019, 2022 etc.), and install a specific version, run:

cmd/modern/root.go

@@ -121,7 +121,7 @@ func (c *Root) addGlobalFlags() {
 		String:        &c.configFilename,
 		DefaultString: config.DefaultFileName(),
 		Name:          "sqlconfig",
-		Usage:         localizer.Sprintf("configuration file"),
+		Usage:         localizer.Sprintf("YAML configuration file (.yaml or .yml extension)"),
 	})
 
 	/* BUG(stuartpa): - At the moment this is a top level flag, but it doesn't

internal/translations/catalog.go

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "Konfigurationsdatei",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",

internal/translations/locales/de-DE/out.gotext.json

@@ -47,9 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "configuration file",
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": "YAML configuration file (.yaml or .yml extension)",
             "translatorComment": "Copied from source.",
             "fuzzy": true
         },

internal/translations/locales/en-US/out.gotext.json

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "archivo de configuración",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",

internal/translations/locales/es-ES/out.gotext.json

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "fichier de configuration",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",

internal/translations/locales/fr-FR/out.gotext.json

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "file di configurazione",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",

internal/translations/locales/it-IT/out.gotext.json

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "構成ファイル",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",

internal/translations/locales/ja-JP/out.gotext.json

@@ -47,11 +47,9 @@
             "fuzzy": true
         },
         {
-            "id": "configuration file",
-            "message": "configuration file",
-            "translation": "구성 파일",
-            "translatorComment": "Copied from source.",
-            "fuzzy": true
+            "id": "YAML configuration file (.yaml or .yml extension)",
+            "message": "YAML configuration file (.yaml or .yml extension)",
+            "translation": ""
         },
         {
             "id": "log level, error=0, warn=1, info=2, debug=3, trace=4",