Merge pull request #64 from metafacture/bestPracticeMacrosAndMaps

Author: TobiasNx

docs/fix/Fix-User-Guide.md

@@ -265,6 +265,7 @@ This page is a replication of the passages [Best practices and guidelines for wo
 - If using a `list` bind with a variable, the `var` option requires quotation marks (`do list(path: "<sourceField>", "var": "<variableName>")`).
 - Fix turns repeated fields into arrays internally but only marked arrays (with `[]` at the end of the field name) are also emitted as "arrays" (entities with indexed literals), all other arrays are emitted as repeated fields.
 - Every Fix file should end with a final newline.
+- We recommend to wrap functions that create maps (e.g. [`put_filemap`](https://metafacture.org/metafacture-documentation/docs/fix/Fix-functions.html#put_filemap), [`put_map`](https://metafacture.org/metafacture-documentation/docs/fix/Fix-functions.html#put_map), [`put_rdfmap`](https://metafacture.org/metafacture-documentation/docs/fix/Fix-functions.html#put_rdfmap)) as well as those that create macros ([`do put_macro`](https://metafacture.org/metafacture-documentation/docs/fix/Fix-functions.html#do-put_macro)) into a [`once` bind](https://metafacture.org/metafacture-documentation/docs/fix/Fix-functions.html#do-once) since maps and macros are saved into memory. You can use one `once` bind for all maps and macros.
 
 ### Glossary