Add: Documentation for opening as Immutable

Author: gjrtimmer

README.md

@@ -80,6 +80,7 @@ Boolean values can be one of:
 | Defer Foreign Keys | `_defer_foreign_keys` \| `_defer_fk` | `boolean` | For more information see [PRAGMA defer_foreign_keys](https://www.sqlite.org/pragma.html#pragma_defer_foreign_keys) |
 | Foreign Keys | `_foreign_keys` \| `_fk` | `boolean` | For more information see [PRAGMA foreign_keys](https://www.sqlite.org/pragma.html#pragma_foreign_keys) |
 | Ignore CHECK Constraints | `_ignore_check_constraints` | `boolean` | For more information see [PRAGMA ignore_check_constraints](https://www.sqlite.org/pragma.html#pragma_ignore_check_constraints) |
+| Immutable | `immutable` | `boolean` | For more information see [Immutable](https://www.sqlite.org/c3ref/open.html) |
 | Journal Mode | `_journal` | <ul><li>DELETE</li><li>TRUNCATE</li><li>PERSIST</li><li>MEMORY</li><li>WAL</li><li>OFF</li></ul> | For more information see [PRAGMA journal_mode](https://www.sqlite.org/pragma.html#pragma_journal_mode) |
 | Locking Mode | `_locking` | <ul><li>NORMAL</li><li>EXCLUSIVE</li></ul> | For more information see [PRAGMA locking_mode](https://www.sqlite.org/pragma.html#pragma_locking_mode) |
 | Mode | `mode` | <ul><li>ro</li><li>rw</li><li>rwc</li><li>memory</li></ul> | Access Mode of the database. For more information see [SQLite Open](https://www.sqlite.org/c3ref/open.html) |

sqlite3.go

@@ -810,6 +810,15 @@ func errorString(err Error) string {
 //       - shared
 //       - private
 //
+//   immutable=Boolean
+//     The immutable parameter is a boolean query parameter that indicates
+//     that the database file is stored on read-only media. When immutable is set,
+//     SQLite assumes that the database file cannot be changed,
+//     even by a process with higher privilege,
+//     and so the database is opened read-only and all locking and change detection is disabled.
+//     Caution: Setting the immutable property on a database file that
+//     does in fact change can result in incorrect query results and/or SQLITE_CORRUPT errors.
+//
 // go-sqlite3 adds the following query parameters to those used by SQLite:
 //   _loc=XXX
 //     Specify location of time format. It's possible to specify "auto".