Add phrase search (#1021)

* Add mentions of phrase search to learn/what_is_meilisearch/featuresd,
reference/api/search, and reference/features/search_parameters

* Update learn/what_is_meilisearch/features.md

Co-authored-by: Guillaume Mourier <[email protected]>

* Update reference/features/search_parameters: mention hard separators; link to
document outlining both soft and hard separators
Update reference/under_the_hood/contact: prefer "phrase search" over "phrase
query" and link to the new phrase search heading

* Update reference/features/search_parameters: add code sample

* Update learn/what_is_meilisearch/features.md

Co-authored-by: Tommy <[email protected]>

* Update reference/features/search_parameters.md

Co-authored-by: Tommy <[email protected]>

* Update reference/features/search_parameters.md

Co-authored-by: Tommy <[email protected]>

* Update learn/what_is_meilisearch/features.md

* Update reference/features/search_parameters.md

Co-authored-by: Tommy <[email protected]>

* Update reference/under_the_hood/concat.md

Co-authored-by: Tommy <[email protected]>

* Update reference/api/search: explicitly mention placeholder/phrase search on
both POST and GET routes

* Apply suggestions from code review

Co-authored-by: Tommy <[email protected]>

Co-authored-by: Guillaume Mourier <[email protected]>
Co-authored-by: Tommy <[email protected]>

Author: 3 people

learn/what_is_meilisearch/features.md

@@ -44,6 +44,12 @@ If you make a search without inputting any query words, MeiliSearch will return
 
 Placeholder search is not affected by MeiliSearch's [default ranking rules](/reference/features/settings.md#ranking-rules)—only custom rules added by a user. If no custom rules have been set, the results are displayed in the order of their internal database position.
 
+## Phrase search
+
+If you enclose search terms in double quotes (`"`), MeiliSearch will only return documents that contain those terms in the order they were given. This gives users the option to make more precise search queries.
+
+Phrase search is particularly useful when looking for a single result, such as searching for a book by ISBN. It is also possible to combine phrase searches with MeiliSearch's basic syntax so only parts of a query are matched strictly.
+
 ## Comprehensive language support
 
 [MeiliSearch is multilingual](/reference/features/language.md)! We aim to support every language represented in our global community.

reference/api/search.md

@@ -41,6 +41,14 @@ This is the preferred route to perform search when an API key is required, as it
 
 [Learn more about how to use the search parameters](/reference/features/search_parameters.md).
 
+#### Placeholder search
+
+When no search query is specified, a [placeholder search](/reference/features/search_parameters.md#query-q) is run instead.
+
+#### Phrase search
+
+Query terms enclosed in double quotes are treated as [phrase searches](/reference/features/search_parameters.md#query-q).
+
 ### Response
 
 | field                | Description                    |    type    |
@@ -131,7 +139,11 @@ This route should only be used when no API key is required. If an API key is req
 
 #### Placeholder search
 
-When the `q` parameter is not specified, a [placeholder](/reference/features/search_parameters.md#query-q) search is run instead.
+When no search query is specified, a [placeholder search](/reference/features/search_parameters.md#query-q) is run instead.
+
+#### Phrase search
+
+Query terms enclosed in double quotes are treated as [phrase searches](/reference/features/search_parameters.md#query-q).
 
 ### Response
 

reference/features/search_parameters.md

@@ -72,6 +72,18 @@ This will give you a list of documents that contain your query terms in at least
 }
 ```
 
+### Phrase search
+
+If you enclose search terms in double quotes (`"`), MeiliSearch will only return documents containing those terms in the order they were given. This is called a **phrase search**.
+
+Phrase searches are case-insensitive and ignore [soft separators such as `-`, `,`, and `:`](/reference/under_the_hood/datatypes.md). Using a hard separator within a phrase search effectively splits it into multiple separate phrase searches: `"Octavia.Butler"` will return the same results as `"Octavia" "Butler"`.
+
+You can combine phrase search and normal queries in a single search request. In this case, MeiliSearch will first fetch all documents with exact matches to the given phrase(s), and [then proceed with its default behavior](/learn/core_concepts/relevancy.md).
+
+#### Example
+
+<CodeSamples id="phrase_search_1" />
+
 ## Offset
 
 **Parameter**: `offset`

reference/under_the_hood/concat.md

@@ -26,7 +26,7 @@ This consists of finding the most interesting place to separate the words and to
 
 This is achieved by finding the best frequency of the separate words in the dictionary of all words in the dataset. It will look out that both words have a minimum of interesting results, and not just one of them.
 
-Split words are not considered as multiple words in a search query because they must stay next to each other, this behavior is called **Phrase Queries**.
+Split words are not considered as multiple words in a search query because they must stay next to each other.
 
 #### Example