Added database tool chapter

Author: NataliaTepluhina

docs/.vuepress/config.js

@@ -77,6 +77,8 @@ module.exports = {
             'data/elasticsearch',
             'data/data-migrations',
             'data/elastic-queries',
+            'data/database-tool',
+            'data/ssr-cache',
           ],
         },
         {

docs/guide/data/database-tool.md

@@ -1,46 +1,59 @@
 # Database tool
 
-Vue Storefront gets it's all data from [vue-storefront-api](https://github.com/DivanteLtd/vue-storefront-api) endpoints, operating on top of Elastic Search data store.
+Vue Storefront gets all its data from [vue-storefront-api](https://github.com/DivanteLtd/vue-storefront-api) endpoints, operating on top of Elastic Search data store.
+
+If you installed the project using `npm run installer` command then, the database has been set up, data imported from demo-dump and everything should be just fine.
 
-If You installed the project using `npm run installer` command then, the database has been set up, data imported from demo-dump and everything should be just fine.
 After some more extensive data operations - like custom imports using [mage2vuestorefront](https://github.com/DivanteLtd/mage2vuestorefront) or [magento1-vsbridge](https://github.com/DivanteLtd/magento1-vsbridge) there is a need to re-index the ElasticSearch and setup the proper metadata for fields.
 
-The main reason You know You must reindex the database is kind of the following error You get from vue-storefront console:
+The main reason you know you must reindex the database is kind of the following error you get from the `vue-storefront` console:
 
 ```json
 Error: {"root_cause":[{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [created_at] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}],"type":"search_phase_execution_exception","reason":"all shards failed","phase":"query","grouped":true,"failed_shards":[{"shard":0,"index":"vue_storefront_catalog_1521776807","node":"xIOeZW2lTwaprGXh6YLyCA","reason":{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [created_at] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}}]}
 ```
 
 In this case there is a db tool inside your local `vue-storefront-api` installation to the rescue.
 
-## Re-indexing existing database
+## Re-indexing an existing database
 
 Please go to `vue-storefront-api` directory and run:
-`npm run db rebuild`
+
+```bash
+npm run db rebuild`
+```
 
 This command will:
 
 - reindex your currently set (in the `config/local.json` config file) elastic search index to temp-one,
 - put the right elastic search mappings on top of the temp index,
 - drop the original index,
-- create the alias with original name to the temp one - so You can use original name without any reference chcanges.
+- create the alias with original name to the temp one - so You can use original name without any reference changes.
 
 You can specify different (than this set in `config/local.json`) index name by running:
-`npm run db rebuild -- --indexName=custom_index_name`
+
+```bash
+npm run db rebuild -- --indexName=custom_index_name
+```
 
 ## Creating the new index
 
 If you like to create new, empty index please run:
-`npm run db new`
+
+```bash
+npm run db new
+```
 
 This tool will drop your current index and create new, empty one with all the metafields set.
 
 You can specify different (than this set in `config/local.json`) index name by running:
-`npm run db rebuild -- --indexName=custom_index_name`
 
-## Chaning the index structure / adding new fields / chaning the types
+```bash
+npm run db rebuild -- --indexName=custom_index_name
+```
+
+## Changing the index structure / adding new fields / changing the types
 
-If You like to extenend the ElasticSearch data structures or map some particular field types. For example after getting kind of this error:
+If you like to extend the ElasticSearch data structures or map some particular field types, for example after getting kind of this error:
 
 ```
 [{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [created_at] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}]
@@ -52,7 +65,10 @@ Please do change the ES schema by modifying:
 - [config/elastic.schema.attribute.extension.json](https://github.com/DivanteLtd/vue-storefront-api/blob/master/config/elastic.schema.attribute.extension.json)
 - [config/elastic.schema.taxrate.extension.json](https://github.com/DivanteLtd/vue-storefront-api/blob/master/config/elastic.schema.taxrate.extension.json)
 
-The format is compliant with ES DSL for schema modifications: https://www.elastic.co/blog/found-elasticsearch-mapping-introduction
+The format is compliant with [ES DSL for schema modifications](https://www.elastic.co/blog/found-elasticsearch-mapping-introduction)
 
 After the changes please do run the following indexing command:
-`npm run db rebuild`
+
+```bash
+npm run db rebuild
+```