docs: Update ODBC driver usage (#615)

* docs: Various updates

* docs: Remove documentation for files restricted to CWD

spiceaidocs/docs/components/data-connectors/odbc.md

@@ -52,6 +52,35 @@ For the best `JOIN` performance, ensure all ODBC datasets from the same database
 
 :::
 
+## ODBC Connection String
+
+The ODBC connection string requires the use of an installed and registered driver based on your system type:
+
+- Unix systems; ODBC driver installations can be managed using [unixODBC](https://www.unixodbc.org/), or directly edited through `/etc/odbc.ini` or `/etc/odbcinst.ini`. For example, in the [Databricks DSN Connection Setup Guide](https://docs.databricks.com/en/integrations/odbc/dsn.html#linux) for Linux.
+- Windows systems; ODBC driver installations are managed using the [ODBC Data Source Administrator](https://support.microsoft.com/en-au/office/administer-odbc-data-sources-b19f856b-5b9b-48c9-8b93-07484bfab5a7).
+
+For an example Unix system with an installed PostgreSQL driver where the contents of `/etc/odbcinst.ini` is:
+
+```ini
+[PostgreSQL Unicode]
+Description=PostgreSQL ODBC driver (Unicode version)
+Driver=psqlodbcw.so
+Setup=libodbcpsqlS.so
+Debug=0
+CommLog=1
+UsageCount=1
+```
+
+The Spice Runtime can use this driver installation where `Driver={PostgreSQL Unicode}` is used in the connection string, like:
+
+```yaml
+datasets:
+  - from: odbc:my_table
+    name: my_dataset
+    params:
+      odbc_connection_string: Driver={PostgreSQL Unicode};Server=localhost;Port=5432;Database=postgres;Uid=myuser;Pwd=mypass
+```
+
 ## Configuration
 
 In addition to the connection string, the following [arrow_odbc builder parameters](https://docs.rs/arrow-odbc/latest/arrow_odbc/struct.OdbcReaderBuilder.html) are exposed as params:

spiceaidocs/docs/components/secret-stores/env/index.md

@@ -67,12 +67,24 @@ MY_PG_PASSWORD=postgres
 
 ### Additional Parameters
 
-To load environment variables from a specific `.env` file, use the `file_path` parameter. When using specific environment variable file using `file_path` environment variables from the default `.env` or `.env.local` files will not be loaded.
+To load environment variables from a specific `.env` file, use the `file_path` parameter. When a `file_path` parameter is specified, environment variables from `.env` or `.env.local` will not be loaded.
 
 ```yaml
 secrets:
   - from: env
     name: env
     params:
-      file_path: /custom/path/to/.env
-```
+      file_path: ./custom/path/to/.env
+```
+
+To continue loading `.env` or `.env.local`, specify them as additional secret stores:
+
+```yaml
+secrets:
+  - from: env
+    name: env
+  - from: env
+    name: env
+    params:
+      file_path: ./custom/path/to/.env
+```

spiceaidocs/docs/components/secret-stores/index.md

@@ -30,6 +30,7 @@ The Secret Store type and name are specified using the `from` and `name` fields.
 Additional parameters may be specified in the `params` field, which are typically specific to the secret store type.
 
 Example:
+
 ```yaml
 secrets:
   - from: kubernetes:my_secret
@@ -43,6 +44,7 @@ secrets:
 Secrets may be used by components with the syntax `${<secret_store_name>:<key_name>}`. For example, to reference a secret stored as an environment variable named `MY_SECRET` in the `env` secret store, use `${env:MY_SECRET}`.
 
 Example:
+
 ```yaml
 datasets:
   - from: postgres:my_table
@@ -67,6 +69,7 @@ datasets:
 The `<secret_store_name>` value in `${<secret_store_name>:<key_name>}` is the `name` value defined in the secret store configuration. This can be renamed to any value.
 
 Example:
+
 ```yaml
 secrets:
   - from: env
@@ -91,6 +94,7 @@ Spice supports configuring multiple secret stores which are loaded in the order
 To load a secret from any of the configured secret stores in precedence order, use the `${secrets:<key_name>}` syntax.
 
 Example:
+
 ```yaml
 secrets:
   - from: env