docs: fix more links

docs/admin/Import.md

@@ -96,7 +96,7 @@ This data can be optionally downloaded into the project directory:
     wget https://www.nominatim.org/data/us_postcodes.csv.gz
 
 You can also add your own custom postcode sources, see
-[Customization of postcodes](Customization.md#external-postcode-data).
+[Customization of postcodes](../customize/Postcodes.md).
 
 ## Choosing the data to import
 

docs/customize/Special-Phrases.md

@@ -2,7 +2,7 @@
 
 ## Importing OSM user-maintained special phrases
 
-As described in the [Import section](Import.md), it is possible to
+As described in the [Import section](../admin/Import.md), it is possible to
 import special phrases from the wiki with the following command:
 
 ```sh

docs/customize/Tokenizers.md

@@ -37,7 +37,7 @@ NOMINATIM_DATABASE_MODULE_PATH=<path to directory where nominatim.so resides>
 ```
 
 This is in particular useful when the database runs on a different server.
-See [Advanced installations](Advanced-Installations.md#importing-nominatim-to-an-external-postgresql-database) for details.
+See [Advanced installations](../admin/Advanced-Installations.md#importing-nominatim-to-an-external-postgresql-database) for details.
 
 There are no other configuration options for the legacy tokenizer. All
 normalization functions are hard-coded.

docs/develop/Tokenizers.md

@@ -6,7 +6,7 @@ tokenizers that use different strategies for normalisation. This page describes
 how tokenizers are expected to work and the public API that needs to be
 implemented when creating a new tokenizer. For information on how to configure
 a specific tokenizer for a database see the
-[tokenizer chapter in the administration guide](../admin/Tokenizers.md).
+[tokenizer chapter in the Customization Guide](../customize/Tokenizers.md).
 
 ## Generic Architecture