Clarify clustering details and remove migration guide (#127)

* Update clustering details in minimizing-costs guide for better clarity

* remove migration guide

* remove all mentions

* rename

* Update src/content/docs/guides/minimizing-costs.md

Co-authored-by: Barry Pollard <barrypollard@google.com>

* Remove 'Migrate queries to `crawl` dataset' link

Signed-off-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>

* simplify title

Signed-off-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>

* adust example

Signed-off-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>

* docs: Update SQL dialect reference and remove migration guide links from guided tour.

Signed-off-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>

---------

Signed-off-by: Max Ostapenko <1611259+max-ostapenko@users.noreply.github.com>
Co-authored-by: Barry Pollard <barrypollard@google.com>

Author: max-ostapenko

astro.config.mjs

@@ -42,7 +42,6 @@ export default defineConfig({
             { label: 'Minimizing query costs', link: '/guides/minimizing-costs/' },
             { label: 'Guided tour', link: '/guides/guided-tour/' },
             { label: 'Release cycle', link: '/guides/release-cycle/' },
-            { label: 'Migrate queries to `crawl` dataset', link: '/guides/migrating-to-crawl-dataset/' },
           ],
         },
         {

src/content/docs/guides/getting-started.mdx

@@ -1,5 +1,5 @@
 ---
-title: Getting started accessing the HTTP Archive with BigQuery
+title: Getting started
 description: Using HTTP Archive on BigQuery for the first time
 ---
 

src/content/docs/guides/guided-tour.mdx

@@ -12,12 +12,7 @@ If you are new to BigQuery, then the [Getting Started guide](/guides/getting-sta
 
 - This guide assumes that you've completed the setup from the [Getting Started guide](/guides/getting-started/).
 - You would be safe processing extremely-large tables contained in this dataset if you follow the [minimizing query costs guide](/guides/minimizing-costs/).
-- It also assumes some familiarity with SQL. All of the examples provided will be using [Standard SQL](https://cloud.google.com/bigquery/docs/reference/standard-sql/).
-
-Migration Guides:
-
-- If you are looking to adapt older HTTP Archive queries, written in [Legacy SQL](https://cloud.google.com/bigquery/docs/reference/legacy-sql), then you may find this [migration guide](https://cloud.google.com/bigquery/docs/reference/standard-sql/migrating-from-legacy-sql) helpful.*
-- If you've been working with the deprecated dataset `pages` or `requests`, there is a guide on [migrating your queries to the `crawl` dataset](/guides/migrating-to-crawl-dataset/).
+- It also assumes some familiarity with [Google SQL](https://docs.cloud.google.com/bigquery/docs/introduction-sql).
 
 This guide is split into multiple sections, each one focusing on different tables in the HTTP Archive. Each section builds on top of the previous one: