Add note on spec

docs/blueql/1.overview.md

@@ -3,8 +3,8 @@ id: overview
 title: Overview
 ---
 
-BlueQL<sup>TM</sup> is Skytable's own query language that very closely follows the design of SQL but with many modern features 
-and superior security. This document explores a basic overview of BlueQL.
+BlueQL<sup>TM</sup> is Skytable's own query language that very closely follows the design of SQL but with many 
+modern features  and superior security. This document explores a basic overview of BlueQL.
 
 Design principles:
 - **Simplicity and clarity**: The language shouldn't be overwhelming to understand
@@ -18,15 +18,20 @@ Just like SQL, BlueQL has three categories of commands/queries inside it:
 
 Jump to [differences from SQL](#differences-from-sql).
 
-## Language specification
+:::info
+This text is *not* a detailed, formal guide. It's meant for developers and users who want to work with 
+Skytable.  If you need a more formal specification, like a grammar definition, please ask us, and we'll create 
+it. We haven't published it yet because no one has requested it.
+:::
 
-### Identifiers
+## Identifiers
 Can begin with any ASCII alphabet or an underscore (`_`) and then have any number of alphanumeric characters and/or underscores.
 
-### Keywords
+## Keywords
 
 Keywords are identifiers with special meanings and hence can't be used as identifiers in other places. Here's a full-list of 
 keywords:
+
 ```ts
 [
     "sysctl", "create", "alter", "drop", "use", "inspect", "describe", "insert", "select", "update",
@@ -38,7 +43,7 @@ keywords:
 ]
 ```
 
-### Data types
+## Data types
 
 #### Boolean
 A boolean value, either `true` or `false`
@@ -82,7 +87,7 @@ A boolean value, either `true` or `false`
 New data types are frequently added, so treat this list as non-exhaustive.
 :::
 
-### Literals
+## Literals
 
 - Null literal: `null`
 - Numeric literals:
@@ -102,7 +107,7 @@ It is very important for you to know that literals are not allowed everywhere. T
 Read below to understand why.
 :::
 
-### Parameters
+## Parameters
 
 All literals apart from dictionaries and lists must be used as parameters. **BlueQL only allows literals as parameters**. For example, using the Rust client, if you were to run this:
 
@@ -133,7 +138,7 @@ source, it becomes a parameter. If you try to not use parameters, the query will
 On a final note, BlueQL doesn't support comments of any form also for security reasons.
 :::
 
-### Expressions
+## Expressions
 
 - `+=`: add RHS to LHS
   - Can be used outside arithmetic contexts