[Doc] Fixed documentation for databricks_schemas data source and `d…

…atabricks_metastore_assignment` resource (#3851)

## Changes
- Fixed typos in `databricks_schemas` data sources doc. Resolve #3849
- Clarified `default_catalog_name` attribute is deprecated. Resolve
#3850

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->

- [x] relevant change in `docs/` folder

docs/data-sources/schema.md

@@ -15,8 +15,8 @@ data "databricks_schemas" "all" {
   catalog_name = "sandbox"
 }
 
-data "databricks_schema" {
-  for_each = data.datatbricks_schemas.all.ids
+data "databricks_schema" "this" {
+  for_each = data.databricks_schemas.all.ids
   name     = each.value
 }
 ```

docs/resources/metastore_assignment.md

@@ -30,7 +30,7 @@ The following arguments are required:
 
 * `metastore_id` - Unique identifier of the parent Metastore
 * `workspace_id` - id of the workspace for the assignment
-* `default_catalog_name` - (Optional) Default catalog used for this assignment, default to `hive_metastore`
+* `default_catalog_name` - (Deprecated) Default catalog used for this assignment. Please use [databricks_default_namespace_setting](default_namespace_setting.md) instead.
 
 ## Attribute Reference