Documentation Fixes (nilearn#2450)

* Tiny aesthetic changes to the main reference page.

* Removed some exceptions from the .gitignore file and added venv/.

* Added a custom CSS rule to give function/method parameter definitions a small space between the name and the description.

* Documentation fixes to the  module as well as a couple of tiny refactor to improve readability.

* Fixed new_img_like() logic broken by last commit.

* Apply suggestions from code review

Co-authored-by: Gael Varoquaux <[email protected]>
Co-authored-by: bthirion <[email protected]>

* Fixed comments from review.

* Reverted title case change and resolved merge problem.

Co-authored-by: Gael Varoquaux <[email protected]>
Co-authored-by: bthirion <[email protected]>

.gitignore

@@ -34,10 +34,6 @@ tags
 *.tgz
 
 .idea/
+venv/
 
 doc/themes/nilearn/static/jquery.js
-!/doc/_build/
-!/.pytest_cache/
-!/build/
-!/doc/auto_examples/
-!/dist/

doc/modules/reference.rst

@@ -1,11 +1,9 @@
-================================================
-Reference documentation: all nilearn functions
-================================================
+===============================================
+ Reference documentation: all nilearn functions
+===============================================
 
 This is the class and function reference of nilearn. Please refer to
-the :ref:`full user guide <user_guide>` for further details, as the class and
-function raw specifications may not be enough to give full guidelines on their
-uses.
+the :ref:`user guide <user_guide>` for more information and usage examples.
 
 .. contents:: **List of modules**
    :local:
@@ -136,7 +134,7 @@ uses.
    Decoder
    DecoderRegressor
    fREMClassifier
-   fREMRegressor 
+   fREMRegressor
    SpaceNetClassifier
    SpaceNetRegressor
    SearchLight

doc/themes/nilearn/static/nature.css_t

@@ -1037,6 +1037,13 @@ table.field-list tr td.field-body p.first {
 table.field-list tr td.field-body p {
     margin-top: 0.5em;
 }
+
+/* Fix spacelessness between parameter name and description */
+dl.field-list span.classifier {
+    margin-left: 1ex;
+}
+
+
 /* ------- tag cloud on the front page -------------------- */
 
 div.tags {
@@ -1723,7 +1730,7 @@ div.body div.sphx-glr-download-link-note {
 
 @media (min-width: 1200px) {
   div.body div.sphx-glr-download-link-note {
-    /* Flush to the left: 50% of viewport width 
+    /* Flush to the left: 50% of viewport width
      * minus half of the bodywrapper width,
      * minus the half width of the sphinxsidebar */
     float: none;

nilearn/image/__init__.py

@@ -1,5 +1,5 @@
 """
-Mathematical operations working on Niimg-like objects like -a (3+n)-D block of
+Mathematical operations working on Niimg-like objects like a (3+)D block of
 data, and an affine.
 """
 from .resampling import resample_img, resample_to_img, reorder_img, \